HomeCasa Prompts

How to write prompts for ChatGPT

Practical tips to get more out of ChatGPT: message structure, custom instructions, long conversations, files and reviewing answers.

ChatGPT understands natural-language instructions, so you do not need special commands. What makes the difference is clarity and context. These tips apply to most models available in ChatGPT; specific features may vary with your plan and version.

For tasks of some complexity, order your message like this:

  1. Role or perspective.
  2. Context and data.
  3. The specific task.
  4. Instructions or steps.
  5. Constraints.
  6. Response format.

You can use headings or lists inside the message: they help both the AI and you when you reuse the prompt.

Use custom instructions

ChatGPT lets you save instructions that apply to all your conversations (for example, your profession, the language you want answers in, or that you prefer short answers). Use them for what you always repeat and keep the prompt for what is specific to each task.

Work in turns

Instead of asking for everything at once:

  • Ask for an outline or proposal first.
  • Correct the course (“drop point 3, expand point 4”).
  • Then ask for the full version.

If a conversation gets very long and starts losing track, open a new one and paste a summary of the important context.

Files, images and data

You can attach documents, spreadsheets or images depending on your account's features. Explain what the file contains and what you want done: “the CSV has one row per order; calculate the average order value per month and show it in a table”.

Do not upload personal data, passwords or confidential information that should not leave your organization.

Example

Act as a high school math teacher.
My 14-year-old daughter does not understand quadratic equations.
Explain it in 4 steps with a solved example, then give 3 exercises
of increasing difficulty with the solutions at the end.
Use simple language and avoid notation you do not explain.

Always review

ChatGPT can make mistakes and present them confidently. For data, figures or quotes, ask for sources or check them yourself. If you use web search inside ChatGPT, review the links it cites.

Ready-to-use prompts

Explore the ChatGPT prompts in the library: each one includes usage instructions and customizable variables.

Learn prompting

  • What is a prompt and how does it work

    A prompt is the instruction you give an artificial intelligence. Learn its parts, why the result depends so much on how you write it, and how to get started.

  • How to create a prompt from scratch

    A 6-step method to go from a vague idea to a clear, reusable prompt, with a complete end-to-end example.

  • How to write effective prompts

    Ten practical principles to write prompts that work on the first try more often: clarity, specificity, examples, format and review.

  • How to write prompts for Claude

    How to write prompts for Anthropic's Claude: direct instructions, rich context, long documents, tags for structure and requests for reasoning.

  • How to write prompts to generate images

    The structure that works best in Midjourney, DALL-E, Stable Diffusion, Flux or Firefly: subject, style, light, composition and parameters, with examples.

  • How to write prompts to generate videos

    How to describe a shot for Runway, Kling, Sora or Veo: one subject, one action, camera movement, light and mood. And how to plan multi-shot videos.

  • How to improve a bad prompt

    A diagnostic process to find out why a prompt is not working and how to fix it, with a before-and-after example and a prompt to let the AI help you.

  • What are variables in a prompt

    Variables turn a prompt into a reusable template. Learn how to define them, name them and use them on HomeCasa Prompts.

  • What is context in a prompt and how much to give

    Context is the information the AI cannot guess. Learn what to include, what to avoid and how to organize documents and data inside a prompt.

  • How to define roles in a prompt

    What telling the AI “act as…” really does, how to choose a good role, combine it with concrete criteria and avoid roles that do not help.

  • How to structure prompt instructions

    Numbered steps, delimiters, sections and logical order: how to organize a long prompt so the AI does not skip anything.

  • Good and bad prompt examples

    Eight comparisons of real prompts for text, code, image and video, explaining what fails in the bad version and what the good one improves.

  • Common mistakes when writing prompts

    The ten most common prompt-writing mistakes and how to avoid them: from missing context to blindly trusting the answer.

  • Advanced prompting techniques

    Few-shot examples, step-by-step reasoning, prompt chaining, self-critique, structured outputs and evaluation: techniques for more reliable results.