Prompt Playbook: Building your first AI App PART 2

Had a proper first-world problem moment a little while back. Needed a storage box for my kitchen - something to fit inside my kitchen cupboards.

What a faff! Spent nearly an hour on a box website (I know right FUN!), squinting at dimensions, trying to work out if each box would fit my space.

Not too big that it wouldn't fit under the desk, not so small there'd be wasted space.

My calculator was getting more action than it had since uni.

Posted about my dimension-induced headache on X/Twitter. Standard moaning British post - "why isn't there a tool for this?".

An hour later, someone dropped in my DMs. "Made you a thing," they said.

What they'd built was dead simple. They'd scraped a list of storage boxes off a popular website, dimensions and all. Added a basic prompt that asked what space you were trying to fill, and it spat back three box recommendations that would fit.

That's it. Basic as anything. But solved the problem perfectly.

The person who built this was Cien - we'll talk more about her tomorrow when we look at the platform she's built. But today I want to focus on crafting that perfect base prompt. The foundation of any AI tool.

Let’s get started

Foundational Prompt

Let's break down exactly what Cien built

1. Input: A list of boxes pulled from a website, including dimensions

2. Process: A prompt that asked users what space they needed to fill and checked their dimensions against the list

3. Output: Three box recommendations that would fit

Boring? Absolutely! But that's exactly why it worked. No fancy features, no complex logic - just a simple tool that solved a specific problem.

And here's the thing - that basic foundation could go anywhere. Polish it up for a few days and you could sell it to box manufacturers for thousands. Or turn it into a tool that recommends boxes on Amazon and collect affiliate fees. Easy money from something that started with a basic prompt.

That's exactly what we're going to build today - that first foundation. The basic building block that proves our idea works and has value. Everything else - platforms, interfaces, fancy features - that all comes later. (And we’ll cover them shortly).

Step 1: ChatGPT Playground

Before we dive into fancy tools or platforms, we're starting in the simplest possible place: ChatGPT's interface. Think of it as your prompt testing ground.

Why ChatGPT first? Because it's fast, forgiving, and free. And….you probably already use it!

You can test and refine your prompt dozens of times without any setup or cost. This is where you'll find the core of what works.

For the box finder, the first tests were just: "Here's a list of boxes [list]. A user needs a box for a space that's [dimensions]. Recommend three that would fit." And an uploaded (or even copy/pasted) list of boxes with their dimensions.

Simple? Yes. But it proved the concept worked before adding any complexity. And that's exactly what we want - proof that our basic idea works.

The One Input → One Output Rule

Here's where most people go wrong - they try to handle multiple cases, add fancy formatting, build in complex logic. Don't! Please! Your first prompt should do ONE thing well.

Think about it like this: Input: What's the ONE thing you're giving the AI? Output: What's the ONE thing you want back?

For Cien's box finder

• Input: Space dimensions

• Output: Three box recommendations

That's it! No fancy formatting. No complex decision trees. Just one thing in, one output out. If you're writing more than three lines of prompt at this stage, you're probably overcomplicating it.

Step 2: Optional Power-Up

Once you've got something working in ChatGPT, you might want to write a more robust prompt from scratch. That's where Claude's prompt creation tool comes in handy.

To access it

1. Head to https://console.anthropic.com/dashboard

2. You'll see a menu with three prompt-focused options

   • Write a prompt from scratch

   • Generate a prompt

   • Improve an existing prompt

It looks like this

You can use Generate a Prompt to help get your first draft prompt done. Make sure to test it!

But here's the thing - this step is optional. If your ChatGPT prompt is working, you can skip straight to step 3. Don't add complexity just because you can.

Step 3: The Final Polish

Using the same Anthropic Console above, select "Improve an existing prompt". The improver excels at making prompts more robust for complex tasks that require high accuracy.

Simply paste in your working prompt and it'll help

• Add clear step-by-step reasoning

• Define explicit output formatting

• Guide the AI through proper analysis

You can also add

• Any specific issues you're seeing (optional)

• Example inputs/outputs if you have them

This may be overkill. It’ll depend on the complexity of the task honestly. The only way to know is to test the prompt - see what it’s results are like and if more refinement is needed.

Testing Your Variations

Whatever stage you're at - ChatGPT testing, prompt creation, or improvement - the key is to test variations. Try different ways of asking for the same thing. You might find that a slight change in wording makes a huge difference in results.

We’ll cover this fully in Part 5 but you can (and should) be testing as you go.

For example, with the box finder

• Version 1: "Find boxes that fit these dimensions"

• Version 2: "Recommend boxes that maximize this space"

• Version 3: "List the three most efficient boxes for this space"

Each slight variation might give you different results. Test them all. Keep what works.

Next we're moving your refined prompt onto a proper platform. That's where we'll meet Cien properly and see how she turned these simple prompts into proper tools.

But right now get something basic working. Then, if you need it, use the prompt creation and improvement tools to make it bulletproof.

Keep Prompting,

Kyle