Rewritten takeaways from the labs that build the models and the universities that teach them, so you can see where they agree and what each adds. Follow the link for the original.
What they all agree on
A filled dot means the guide makes this point explicitly.
Advice
Anthropic
OpenAI
Google
NVIDIA
MIT Sloan
Harvard
xAI
Meta
Be specific about the task, format and length.
Provide context and audience.
Use examples to show the pattern you want.
Structure long prompts with tags or headers.
Break complex work into steps.
Test and iterate on real inputs.
Verify facts and citations yourself.
Anthropic
Prompt engineering overview and Claude best practices
Clarity, context and structure for Claude models, plus agentic and long-horizon prompting.
Standout idea
Explain why. A constraint with its reason behind it lets the model handle cases you never wrote a rule for.
Be clear and direct: treat Claude like a brilliant new employee who lacks your context.
Add the reason behind instructions; Claude generalises from explanations.
Use XML tags to separate instructions, documents and examples.
Place long documents at the top of the prompt and the query at the end.
Current models follow instructions precisely, so dial down aggressive emphasis that older models needed.
For long agent runs, have the model keep state in files and verify its work with tests.
Best for: Anyone writing system prompts or agent briefs, on any model.
OpenAI
Prompt engineering and GPT model prompting guides
Instruction hierarchy, reasoning models, structured outputs and agentic workflows for GPT models.
Standout idea
Give reasoning models the destination, not the route. Over-specified steps often hurt.
Put durable instructions in developer or system messages; keep user messages for the task.
Reasoning models work best with high-level goals; avoid telling them how to think.
Use Structured Outputs with a JSON schema when a program reads the result.
Markdown headers and XML tags help the model parse long prompts.
For agents, tell the model to keep going until the task is fully resolved and to use tools rather than guess.
Pin model versions and evaluate prompt changes against a test set.
Best for: Developers building on the OpenAI API and agent builders.
Google
Gemini prompt design strategies
Clear instructions, few-shot examples, context and multimodal prompting for Gemini.
Standout idea
Few-shot by default. Google's own testing found examples are the most reliable lever.
Always include few-shot examples when you can; prompts without them are less effective.
Show positive patterns to follow rather than anti-patterns to avoid.
Use prefixes (Input:, Output:) to signal structure.
Break complex tasks into components and chain them.
For images and video, put the media before the text instruction.
Experiment with temperature and other parameters as part of prompt design.
Best for: Multimodal prompts and teams building on Gemini.
NVIDIA
Prompt engineering and P-tuning for large language models
How prompting relates to model internals, and when to move from prompts to tuning.
Standout idea
Know when to stop prompting. If you are fighting the model with ever-longer prompts, tuning may be cheaper.
Prompts steer a fixed model; parameter-efficient tuning changes behaviour more durably.
Few-shot prompting trades context length for task performance.
Chain-of-thought helps on multi-step arithmetic and logic.
When prompts get long and brittle, consider prompt tuning or fine-tuning instead.
Measure on a held-out set; prompt gains often do not transfer across models.
Best for: ML engineers deciding between prompting, RAG and fine-tuning.
MIT Sloan
Effective prompts for AI: the essentials
Practical prompting for educators and professionals new to generative AI.
Standout idea
Treat it as a conversation. Iterating in the same thread is often faster than crafting a perfect first prompt.
Provide context: who you are, who the output is for, and why.
Be specific about format, length and tone.
Build on the conversation; refine instead of starting over.
Ask the model to take on a perspective relevant to the task.
Always verify facts and citations independently.
Best for: Beginners and educators.
Harvard University IT
Getting started with prompts for text-based generative AI tools
A beginner-friendly checklist for clear, safe prompting in academic and work settings.
Standout idea
Data care is part of prompting: know what you are allowed to paste before you paste it.
Be specific about the task and desired output.
Give the AI a role and an audience.
Use do and don't lists to set boundaries.
Ask for multiple options and choose.
Do not paste confidential data into tools your institution has not approved.
Best for: Students, staff and anyone in a regulated environment.
xAI
Prompt engineering for Grok
Getting fast, precise results from Grok, especially for agentic coding.
Standout idea
Speed changes strategy: with a very fast model, iterate quickly instead of perfecting one big prompt.
Provide the relevant context explicitly: file paths, dependencies and code.
Set explicit goals and requirements; vague prompts waste iterations.
Use fast models for quick iteration and refine with follow-ups.
Lean on native tool calling rather than describing tools in prose.
Detailed system prompts measurably help in agentic setups.
Best for: Developers using Grok for coding and agent tasks.
Meta
Llama prompting guide
Prompting open-weights Llama models, including chat templates and limitations.
Standout idea
Templates matter for open models: the wrong chat format silently costs quality.
Use the model's official chat template exactly; formatting errors degrade quality.
Explicit instructions about style and length work well.
Few-shot and chain-of-thought help smaller models more than large ones.
Restrict extraneous tokens by specifying output format.
Expect to tune prompts per model size.
Best for: Teams self-hosting open-weights models.
Takeaways are our own paraphrased summaries, not quotations. Guides change often; always check the original for the latest advice.