Prompting

Writing Your First Real Prompt

Vibe Coder 101 · Phase 1: Foundations · Stage 4 of 38 · about 12 min · Weekend track

Think about ordering a sandwich.

If you say "food, please", you get whatever the kitchen felt like. If you say "turkey on wheat, no mayo, extra pickles, cut in half", you get your sandwich.

Prompts work exactly the same way. The AI is not reading your mind — it is filling in every blank you leave. The more blanks, the more it guesses.

The four things to say

Before you type anything, answer these four questions about your idea:

  • What does it do? The one-sentence job of the app.
  • Who uses it, and how? What they click, type, or see first.
  • What should it look like? Simple and clean? Dark? Big buttons? Say so.
  • What happens when things go wrong? Empty list, bad input, nothing typed yet.

That fourth one is the one everybody skips, and it is the one that separates a demo from something that actually holds up.

Weak versus strong

Weak:

Make me a to-do list app.

You will get a to-do list. Probably fine. Probably not yours.

Strong:

Make a single-page to-do list I can use on my phone. I can type a task and press Enter to add it. Each task has a checkbox; checking it crosses the task out and moves it to the bottom. There is a small X to delete a task, and it asks me to confirm first. Tasks are saved so they are still there when I come back. If there are no tasks yet, show a friendly message telling me to add my first one. Clean and simple, plenty of white space, big enough to tap with a thumb.

Same app. Wildly different result. Notice that the second one is not technical — there is not a single piece of jargon in it. It is just specific.

Say what you do not want, too

AI tools love to add things. If you do not want a login screen, five extra pages, or a sign-up form, say so:

No login, no accounts, no database — keep it to a single page.

This one line saves an enormous amount of confusion in your first week.

Ask in slices

Do not ask for the whole finished app in one go. Ask for the core, get it working, then add one thing at a time.

Round one: adding and showing tasks. Round two: the checkbox. Round three: saving them. Each round is small enough that when something breaks, you know exactly what broke it — because you only changed one thing.

This is the single most useful habit in this whole course.

Your turn

Take the small idea you wrote down in stage 1 and write a real prompt for it using the four questions. Aim for a solid paragraph — roughly the length of the strong example above.

Then send it, and keep whatever comes back. Do not worry yet about whether it is any good. In the next stage you are going to run it and find out for yourself.

When you want to go deeper on this, How to Write Prompts That Generate Clean Code covers the same ground for bigger projects.