You ask ChatGPT a question and get back something correct but bland, generic, only half usable. The problem is rarely the model — it's the instructions. A prompt is a brief. If you ask a competent person to “write me a LinkedIn post,” you'll get an average LinkedIn post. With AI, it works exactly the same way.

This page gives you a repeatable method: a 6-block structure to fill in order, a complete before/after example on a real case, the techniques that make the biggest difference, three ways to practice, and the most common mistakes. No technical skills required: writing a good prompt means clearly describing what you want, who it's for, why, and in what shape. Budget ten minutes of reading, then an hour of practice to make it a reflex.

What separates a good prompt from a bad one

A good prompt contains everything a competent person would have needed to know before starting the work.

An AI model doesn't guess your intent. It generates the most likely continuation of your text, based on what you gave it. When your request is vague, the most likely continuation is also the most generic: an average text, written for no one in particular. That's not a flaw in the tool, it's a mechanical consequence of missing information.

Here's what a failed prompt is almost always missing:

  • who the result is for (a client, your boss, a 10-year-old, just you);
  • what it will be used for (sending an email, prepping a meeting, publishing an article);
  • the expected tone (direct, warm, formal, technical);
  • length and format (5 bullets, a table, 300 words, an email subject line);
  • the real information to use (numbers, names, context from your company);
  • what the AI is not allowed to invent.

Compare these two instructions. “Summarize this text” produces a neutral summary of unpredictable length. “Summarize these meeting notes in 5 bullets max, one bullet per decision made, with the owner's name and the deadline in parentheses, without rehashing the discussion” produces something you can paste straight into an email.

One thing that often surprises beginners: length isn't the criterion. A precise 40-word prompt beats a fuzzy 300-word one. What matters is the density of useful information.

The 6-block structure of an effective prompt

A solid prompt is always built in the same order: role, goal, context, constraints, format, examples.

Block Question it answers Short example
Role Who's speaking? You're the customer service manager for an online store.
Goal What result do I want? Write a reply to a customer upset about a late delivery.
Context What real info? Order placed March 12, 6 days late, cause: supplier shortage.
Constraints What limits? 120 words max, no promise of a refund, calm tone.
Format In what shape? An email subject line, then the body of the message.
Examples What should it look like? Here are two replies we've already sent and approved.

Role

Giving a role shapes the vocabulary and the level of detail. “You're a ninth-grade math teacher” and “you're a statistics researcher” won't produce the same explanation of the same formula. Stay realistic: a useful role describes a job and a level, not a superlative like “world's best expert.”

Goal

One action verb, one deliverable, one main task. “Analyze and write and translate and publish” in a single prompt gives you four sloppy jobs. Split them up.

Context

This is the block that makes the biggest difference, and the one people skip most. The AI doesn't know your company, your customers, or your constraints. Paste in your real data: email excerpts, numbers, notes, a page from your site. Without context, the AI fills the gaps by making things up.

Constraints

Length, tone, banned words, angle, what absolutely must not happen. Phrase your constraints positively when you can: “write sentences under 20 words” works better than “don't write long sentences.”

Format

Describe the output like a mold: a 3-column table, a numbered list, JSON, a script with timestamps, an email with a subject line. If you're reusing the result in another tool, say so.

Examples

Two or three examples of what you expect beat a paragraph of explanation. It's the highest-return technique of all, covered in detail in our guide to few-shot prompting.

Full example: from a shaky prompt to one that works

The same need, written twice: the difference comes down to six added lines.

The situation: you need to follow up with a client who hasn't responded to a quote you sent two weeks ago.

The shaky prompt:

Write a follow-up email for a client who hasn't responded to my quote.

Typical result: a polite, generic email with phrases like “I just wanted to follow up” and “please don't hesitate to reach out.” Usable, but you'll end up rewriting all of it.

The worked prompt:

You're a salesperson at a 6-person graphic design agency.

Goal: write a follow-up email to a prospect who hasn't responded to a quote.

Context: a €4,200 quote sent on August 18 for rebranding a restaurant's visual identity. The contact is Julien, the owner. We spoke twice by phone, he was very interested, he was waiting on his business partner's approval. Our production slots are filling up for October.

Constraints: 100 words max, no overly familiar tone, direct and non-pushy, a single question at the end, no discount offer, don't write “I just wanted to.”

Format: an email subject line under 50 characters, then the body of the message.

Give me 2 versions: one focused on the scheduling constraint, one focused on helping his partner decide.

This prompt gives you an email you can send after a thirty-second proofread. The blocks you added are exactly the ones a colleague would have asked you about before writing.

Then you iterate instead of starting over. Round 2: “Version 1 is the right one. Shorten the subject line and replace the last sentence with a closed question.” Round 3: “Keep this email and write the next follow-up, to be sent 10 days later if there's still no reply.” Three short exchanges consistently beat trying to nail the perfect prompt on the first try.

The techniques that improve results the most

Four moves cover the vast majority of everyday use cases.

  1. Give examples. Paste in two or three past pieces you like, and say what you like about them (the rhythm, the structure, the level of detail). AI imitates better than it obeys adjectives.
  2. Ask for step-by-step reasoning. For a calculation, a comparison, a diagnosis, add “walk through your reasoning step by step before giving the final answer.” Error rates drop noticeably on multi-step tasks. That's the chain-of-thought principle.
  3. Flip the questions around. End your prompt with “before answering, ask me the 3 questions you need answered to do this job properly.” You discover what you forgot to specify, which improves the next prompt.
  4. Break big tasks apart. A full article, a launch plan, a data analysis: ask for the outline first, approve it, then have it written section by section. Each approved step becomes context for the next.

The teams building these models publish their own recommendations, and they line up with this logic. Anthropic's official prompt engineering documentation, for example, emphasizes clear instructions, examples, and using tags to separate the parts of a prompt. For a broader overview of the techniques, our complete prompt engineering guide walks through them one by one with examples.

Where to practice writing good prompts: 3 methods

Progress comes from repetition on your real work, not from reading articles. Here are three ways to get started, from the most structured to the most self-directed.

Method 1: a guided program with the tools included (Skilzy)

Skilzy is a French e-learning platform built both for learning AI and for using it. The prompt fundamentals program takes you from the 6-block structure to reusable prompts for your job, with graded exercises instead of theory.

What's different from a traditional course: the built-in AI Lab. You write your prompts and run them on real tools (text, image, video, music, voiceover) with credits included, without stacking up five subscriptions. The platform's other programs (more than 15 in total) cover image and video creation, automation with n8n, and AI-assisted coding.

Two state-recognized, fundable certifications are available: RS7439, AI content marketing and RS6792, AI and sales. B2C access starts at €29.90 per month with no commitment, and there's a B2B offer for training organizations.

To try it without a credit card, the discovery demo gives you 7 days with 1 image, 1 video, 1 music track, and 10 messages. It's the only card-free entry point, and it's enough to check whether the format suits you.

Method 2: the free versions of ChatGPT, Claude, or Gemini

All three major assistants offer a free tier with a daily message quota. It's the cheapest way to practice, and it works very well for text.

What you get: zero cost, immediate availability, the ability to compare answers across models on the same prompt.

What you lose: no structured progression, no feedback on the quality of your prompts, quotas that cut you off in the middle of an exercise, and advanced features (image, video, large files) often reserved for paid tiers. If you're truly starting out, begin with our guide on using ChatGPT as a beginner, then commit to one work task a day for two weeks.

Method 3: public prompt libraries

Free libraries exist from the model providers themselves and on GitHub, with hundreds of copy-ready prompts. They're useful for getting moving fast on a task you don't know how to frame.

The limitation is real: a prompt copied without context gives a generic result, because it contains nothing about your company or your constraints. Use it as a skeleton, then fill in the context and constraints blocks with your own information. That's the difference between a prompt that works for its author and a prompt that works for you.

The mistakes that come up most often

Most bad results come from five habits that are easy to fix.

  • Stacking ten requests into one message. One task per prompt, then move on to the next.
  • Only saying what you don't want. A list of prohibitions with no clear direction produces cautious, hollow text. Describe the target.
  • Forgetting the audience. The same content for an expert and for a total beginner gives two very different texts, and the AI will default to the middle.
  • Accepting the first answer. The first version is a draft to react to, not a deliverable.
  • Trusting the numbers and sources it cites. AI can produce a reference that doesn't exist. Check every number, every date, and every link before publishing.

A sixth missing habit costs you over time: never saving your prompts. Keep a simple document with your 10 best prompts, sorted by task, and replace the variable data with brackets to fill in. These traps are covered in detail in our article on the most common prompting mistakes.

Start practicing today

Take a task you handed to an AI this week and rewrite your request using the 6 blocks: role, goal, context, constraints, format, examples. Compare the two results side by side. It's the fastest exercise for understanding where the quality of an answer actually comes from, and it takes no more than ten minutes.