9. Common mistakes

Even knowing the right techniques, it is easy to fall into traps that reduce the effectiveness of your prompts.

Mistake 1: Ambiguity

Ambiguous prompt:

Write about marketing.

Clear prompt:

Write a 500-word guide about digital marketing for small local businesses with a limited budget. Focus on free strategies. Include 5 specific tactics with examples.

Mistake 2: Lack of context

Without context:

Should I accept the offer?

With context:

I'm 28 years old, I work as a graphic designer at a small agency earning €30,000 a year. I've been offered a position at a startup for €38,000 plus 0.5% equity, but without guaranteed stability. I have a mortgage and I value security but also growth. What factors should I consider?

Mistake 3: Contradictory instructions

Contradictory:

Write a very detailed and in-depth article about AI, maximum 100 words.

Coherent:

Write a 100-word executive summary about AI that highlights the 3 most important applications in today's business.

Mistake 4: Too generic

Generic:

Give me life advice.

Specific:

I'm 35 years old and I feel like I'm in a professional rut. I've worked in accounting for 10 years, it's stable but I'm not passionate about it. I have a family and a mortgage. Give me 5 specific tips to rediscover motivation without putting my economic stability at risk.

Mistake 5: Forgetting the audience

Without an audience:

Explain what photosynthesis is.

With an audience:

Explain what photosynthesis is to an 8-year-old child using simple analogies and everyday language. Maximum 150 words.

Mistake 6: Not iterating or refining

The best prompts come from iteration. Accept that the first version is rarely perfect, analyze what to improve, and save successful versions to reuse.

Quick checklist before sending

• [ ] Is it clear and direct?
• [ ] Have I provided enough context?
• [ ] Have I specified the desired format?
• [ ] Have I indicated the target audience?
• [ ] Are the instructions coherent?
• [ ] Could a colleague understand what I want?

Knowing the most common mistakes is as important as mastering the right techniques. Ambiguity, lack of context, contradictory instructions, and forgetting the audience are traps that even experienced users run into.

Now that you have mastered both the right techniques and the mistakes to avoid, it is time to apply all this to a specific use case. In the next lesson you will see how to adapt these principles to software development: generating code, debugging, refactoring, and writing tests with professional prompts.