How to Write Perfect Veo 3 Prompts with a Custom GPT

8/14/2025

How to Use a Custom GPT to Write Perfect Veo 3 Prompts

Hey everyone, let's talk about something that's been blowing my mind lately: Google's Veo 3. If you're into AI & content creation, you've probably heard the buzz. This thing is a game-changer for video. But here's the thing, like any powerful tool, you need to know how to use it right to get the magic to happen. & that all comes down to the prompt.

Honestly, writing prompts for these advanced AI models is becoming a skill in itself. It's part art, part science. Get it right, & you can create some truly stunning, professional-looking videos. Get it wrong, & you're left with a jumbled mess that looks nothing like what you had in your head.

So, I've been deep in the trenches, figuring out the best ways to prompt Veo 3. & I've come up with a pretty cool system that I want to share with you. It involves creating your own Custom GPT to do the heavy lifting. Think of it as your personal prompt-writing assistant, trained to think exactly how you need it to for amazing video results.

We're going to cover everything from what makes Veo 3 so special, to the nitty-gritty of crafting the perfect prompt, & then the full step-by-step on building your own "Veo 3 Promptsmith" GPT. It's going to be a deep dive, so grab a coffee & let's get into it.

What's the Big Deal with Veo 3 Anyway?

First off, in case you're not fully up to speed, Veo 3 is Google's latest & greatest AI video generation model. It was announced at Google I/O 2025, & it's a pretty significant leap forward from what we've seen before.

What really sets Veo 3 apart is its ability to generate high-definition video with native audio. This isn't just some background music slapped on top of a silent clip. We're talking synchronized dialogue, ambient sounds, sound effects, & music, all generated together. This means you can have characters speaking with realistic lip-syncing, or create a scene with the subtle, immersive sounds of the environment. It's a huge step towards making AI-generated video feel truly lifelike.

Beyond the audio, Veo 3 has some other serious upgrades. It's got a much better grasp on real-world physics, so motion looks more natural. It's also got improved prompt adherence, meaning it's better at actually understanding & following the instructions you give it. This is HUGE, because with earlier models, you'd often find the AI going off on a tangent & ignoring key parts of your prompt.

Right now, getting your hands on Veo 3 is a bit exclusive. It's available in the U.S. through Google's new AI filmmaking interface, Flow, & you'll need an AI Ultra plan. This costs a pretty penny, around $250 a month, & each video generation uses up credits. This is another reason why getting your prompts right from the start is so important. You don't want to waste those precious credits on failed experiments.

So, the takeaway here is that Veo 3 is an incredibly powerful tool for creators, but to really unlock its potential, you need to master the art of the prompt.

The Anatomy of a Perfect Veo 3 Prompt

Writing a good prompt for an AI video generator is a lot like being a director, a cinematographer, & a sound designer all at once. You need to paint a clear picture in the AI's "mind" of exactly what you want to see & hear. Let's break down the key ingredients.

1. The Core Components: Subject, Action, & Scene

This is the foundation of your prompt. You need to be crystal clear about who or what is in the video, what they're doing, & where it's all happening.

Subject: Be specific. Instead of "a man," try "a grizzled old sailor with a thick grey beard & a knitted blue sailor hat." Describe their appearance, clothes, & even their emotions.
Action: What is the subject doing? The action is the heart of your video's story. Keep it focused on a single, clear motion, especially for shorter clips. For example, instead of "a person working," say "a young woman in a red coat walking slowly through a foggy forest at dawn."
Scene: This is your setting. Describe the foreground, background, & any important elements that set the mood. Think about the time of day, the weather, & the overall atmosphere.

2. The Director's Eye: Camera Shots, Angles, & Movement

How the scene is filmed is just as important as what's in it. Adding camera instructions to your prompt gives you a ton of creative control.

Camera Shots: Are we up close or far away? Use terms like "close-up," "medium shot," or "wide shot."
Camera Angles: Where is the camera positioned? "Low-angle shot" can make a subject seem powerful, while an "overhead view" can give a sense of scale.
Camera Movement: Is the camera static or moving? Simple movements like "zoom in," "pan left," or "tracking shot" can add a lot of dynamism to your video. But a word of caution: avoid overly complex camera movements, as AI can sometimes struggle with them.

3. The Artist's Touch: Style & Lighting

This is where you define the visual aesthetic of your video.

Style: Do you want something photorealistic, cinematic, or maybe even animated? You can use keywords to guide the AI towards a specific look. For example, you could ask for "a grainy, black-and-white film noir style" or "a vibrant, colorful anime style."
Lighting: Lighting is crucial for setting the mood. Is it "soft, natural morning light," "harsh, direct sunlight," or "dramatic, high-contrast lighting"? Be descriptive.

4. The Soundscape: Audio Cues for Veo 3

This is the new frontier with Veo 3. You can now direct the audio as well as the visuals.

Dialogue: You can actually include lines of dialogue in your prompt. The AI will attempt to generate a character speaking those lines with synchronized lip movements. For instance, you could have a character say, "This ocean, it's a force, a wild, untamed might."
Sound Effects: What sounds should be in the scene? Mention things like "the chirping of birds," "the roar of a distant lion," or "the clatter of plates in a busy kitchen."
Ambient Noise: This is the subtle background sound that makes a scene feel real. Think "the gentle hum of a refrigerator," "the distant sound of city traffic," or "the rustling of leaves in the wind."
Music: You can also request a certain style of music, like "an upbeat, energetic pop track" or "a slow, melancholic piano melody."

Putting it all together, a good Veo 3 prompt might look something like this:

"A medium shot of a young woman with curly red hair, sitting at a wooden desk in a cozy, sunlit attic. She's typing on a vintage typewriter, a focused expression on her face. The camera slowly zooms in on her hands. The only sounds are the rhythmic clacking of the typewriter keys & the faint chirping of birds outside the window."

See how much more information that gives the AI to work with compared to just "a woman writing"? That's the level of detail we're aiming for.

Building Your "Veo 3 Promptsmith": A Step-by-Step Guide

Okay, so now that we know what goes into a great prompt, how do we make the process easier & more consistent? By building a Custom GPT, of course. For those who aren't familiar, a Custom GPT is a personalized version of ChatGPT that you can tailor for a specific task. You can give it its own instructions, knowledge, & capabilities. It's like having an AI assistant that's already an expert in whatever you need it to do.

We're going to create a Custom GPT that's an expert in writing Veo 3 prompts. We'll call it the "Veo 3 Promptsmith." Here's how to do it.

Step 1: Getting Started

First things first, you'll need a ChatGPT Plus or Enterprise account to create a Custom GPT. Once you're logged in, go to the "Explore GPTs" section & click "Create."

You'll see a screen with two tabs: "Create" & "Configure." The "Create" tab is a chat-based builder that can help you get started, but for maximum control, I recommend heading straight to the "Configure" tab. This is where we'll do all the heavy lifting.

Step 2: Naming Your GPT & Giving it a Personality

In the "Configure" tab, the first thing you'll do is give your GPT a name & a description. Let's call it "Veo 3 Promptsmith." For the description, something like "A specialized AI assistant for crafting detailed, effective prompts for Google's Veo 3 video generation model."

You can also give your GPT a profile picture. You can upload your own or have DALL-E 3 generate one for you.

Now for the most important part: the "Instructions." This is where you tell your GPT who it is, what it does, & how it should behave. This is where we'll input all our knowledge about what makes a great Veo 3 prompt.

Here's a template for the kind of instructions you can use. Feel free to copy & paste this into the instructions box & then customize it to your liking.

Identity & Goal: You are the "Veo 3 Promptsmith," an expert in crafting detailed, effective, & creative prompts for Google's Veo 3 AI video generation model. Your primary goal is to help users translate their ideas into comprehensive prompts that will produce high-quality, accurate, & visually stunning videos.
Core Knowledge: You have a deep understanding of the key components of a great video prompt, including:
Subject: Detailed descriptions of people, animals, or objects.
Action: Clear & focused descriptions of what the subject is doing.
Scene: Rich descriptions of the environment, including foreground, background, & atmosphere.
Camera: Specific instructions for camera shots (close-up, medium shot, wide shot), angles (low-angle, overhead), & movement (pan, zoom, tracking shot).
Style & Lighting: Clear guidance on the visual aesthetic (e.g., photorealistic, cinematic, film noir) & lighting conditions (e.g., golden hour, soft morning light, high-contrast).
Audio: Detailed cues for dialogue, sound effects, ambient noise, & music.
Behavior & Rules:
ALWAYS ask clarifying questions to better understand the user's vision before generating a prompt.
When a user gives you a simple idea, your job is to flesh it out into a detailed prompt.
Structure your final prompts in a clear, organized way, using markdown for headings (e.g., Scene:, Action:, Camera:, Audio:).
Offer multiple prompt variations (e.g., one focused on a cinematic style, another on a more natural, realistic style).
NEVER generate a prompt that is vague or overly simple.
ALWAYS remind the user of the importance of being specific.
If the user's request is too complex for a single shot (e.g., involves multiple scene changes), advise them to break it down into separate prompts.
You can use the web browsing capability to research specific visual styles or locations if the user requests it.

These instructions give our GPT a clear persona, a defined purpose, & a set of rules to follow. This will ensure that its responses are consistent & helpful.

Step 3: Adding Conversation Starters

Next, you can add some "Conversation Starters." These are pre-written prompts that will appear when a user first opens your GPT, making it easier for them to get started. Here are a few good ones for our Veo 3 Promptsmith:

"Generate a prompt for a short, cinematic product ad."
"Help me write a prompt for a nature documentary scene."
"I have a character in mind. Can you help me build a prompt around them?"
"Create a prompt for a spooky, atmospheric scene in a haunted house."

Step 4: Uploading Knowledge (Optional but Recommended)

The "Knowledge" section allows you to upload files that your GPT can reference. This is a great way to give it even more specialized information without cluttering up the instructions. For our Veo 3 Promptsmith, you could create a simple text file with a list of different camera shots, lighting styles, & visual aesthetics. This will give it a richer vocabulary to draw from when crafting prompts.

For example, you could create a file called "filmmaking_terms.txt" with content like:

Camera Shots:
Extreme Wide Shot (EWS)
Wide Shot (WS)
Full Shot (FS)
Medium Wide Shot (MWS)
Cowboy Shot
Medium Shot (MS)
Medium Close-Up (MCU)
Close-Up (CU)
Extreme Close-Up (ECU)
Lighting Styles:
High-Key Lighting
Low-Key Lighting
Three-Point Lighting
Rembrandt Lighting
Golden Hour
Blue Hour

If you upload a knowledge file, make sure you enable the "Code Interpreter" capability, as this is what allows the GPT to read & process the file.

Step 5: Setting Capabilities

In the "Capabilities" section, you can choose what your GPT is allowed to do. For our Promptsmith, I'd recommend enabling:

Web Browsing: This is useful if a user asks for a prompt in the style of a specific director or movie, as the GPT can research that style.
DALL-E Image Generation: This is a fun one. You could ask the Promptsmith to generate a still image to serve as a visual reference for the prompt it creates.
Code Interpreter: As mentioned, this is necessary if you've uploaded any knowledge files.

Step 6: Testing & Refining

Now for the fun part. On the right side of the screen, you'll see a "Preview" window. This is a live version of your GPT that you can interact with as you build it. Use this to test it out & see how it responds.

Try giving it a simple idea, like "a cat in a library." See how it fleshes it out. Does it ask clarifying questions? Does it structure the prompt in the way you specified in the instructions?

If the responses aren't quite right, go back to your instructions & tweak them. The more specific you are in your instructions, the better your GPT will perform.

Step 7: Publishing Your GPT

Once you're happy with how your Veo 3 Promptsmith is working, it's time to publish it. Click the "Create" or "Update" button in the top right corner. You'll have the option to publish it just for yourself, for anyone with a link, or to the public GPT Store.

And that's it! You now have your very own AI assistant, custom-built for the task of writing perfect Veo 3 prompts.

Putting it All Together: Interacting with Your Promptsmith

So, what does this look like in practice? Let's say you're a small business owner who wants to create a short promotional video for your new line of handmade coffee mugs. Instead of staring at a blank screen trying to come up with a prompt, you can just chat with your Veo 3 Promptsmith.

You: "Hey, I need a prompt for a short video about my new handmade coffee mugs. I want it to feel warm & cozy."

Veo 3 Promptsmith: "That sounds great! I can definitely help with that. To make the prompt as effective as possible, could you tell me a bit more? For example:

What does the mug look like? Any specific colors or textures?
Where do you imagine this scene taking place? A coffee shop, a home kitchen?
Is there a person in the video, or is the focus just on the mug?"

See how it's already using the instructions we gave it to ask clarifying questions? This is where the magic happens. A good prompt is a collaborative process, & your Custom GPT can guide you through it.

This same principle of guided interaction is something we think about a lot at Arsturn. When businesses use Arsturn to create custom AI chatbots for their websites, they're essentially doing the same thing: creating a specialized AI assistant. These chatbots are trained on a company's own data, so they can provide instant, accurate answers to customer questions, guide them to the right products, & engage with them 24/7. It's all about creating a more personalized & efficient customer experience, which is exactly what our Promptsmith is doing for the creative process.

After a bit more back-and-forth, the Promptsmith might generate a prompt like this:

Generated Prompt for "Cozy Coffee Mug" Video:
Scene: A close-up shot of a beautifully crafted, earth-toned ceramic coffee mug resting on a rustic wooden table. The mug is filled with steaming hot coffee, with a delicate latte art heart on top. In the background, a soft, out-of-focus fireplace crackles warmly. The lighting is soft & inviting, reminiscent of a lazy Sunday morning.
Action: A pair of hands gently wraps around the mug, lifting it slowly towards the camera. Steam curls up from the coffee, catching the light.
Camera: The shot starts as a close-up on the mug, then slowly pulls back to a medium shot to reveal a person with a cozy sweater, smiling contentedly as they hold the mug.
Audio: The primary sound is the gentle crackling of the fireplace. There's also the subtle sound of a soft, acoustic guitar melody playing in the background. No dialogue.

Now that is a prompt that Veo 3 can really work with. It's detailed, it's evocative, & it covers all the key elements we talked about.

Final Thoughts

The world of AI content creation is moving at a breakneck pace, & tools like Veo 3 are opening up possibilities that were unimaginable just a few years ago. But as the tools get more powerful, the importance of human creativity & direction only increases.

Learning how to write a great prompt is a skill that will serve you well in this new landscape. & building your own Custom GPTs to streamline that process is a fantastic way to level up your workflow. It's not about replacing your own creativity; it's about building a tool that enhances it.

For businesses, this kind of AI-powered assistance is becoming more & more crucial. Whether it's generating marketing content with a tool like Veo 3, or improving website engagement & lead generation with a conversational AI platform like Arsturn, the goal is the same: to build meaningful connections & achieve your goals more effectively. Arsturn helps businesses build these no-code AI chatbots, trained on their own data, to boost conversions & provide those personalized customer experiences that really make a difference.

So, I encourage you to give this a try. Play around with building your own Custom GPT. It's easier than you think, & it's a great way to get a deeper understanding of how these AI models work.

I hope this was helpful. I'm really excited to see the kinds of amazing things people will create with Veo 3, & I think having a solid prompting strategy is the key to unlocking its full potential. Let me know what you think, & happy creating!