Gemini Custom Instructions: How to Write Them, With Examples

Summary

• Custom instructions are reusable guidance you give Gemini so it responds in your preferred style, format, and level of detail.
• Strong instructions are specific, testable, and scoped (what to do, what to avoid, and how to format the output).
• This guide includes ready-to-copy Gemini custom instructions examples for work, school, coding, and everyday tasks.
• You will also learn common failure modes (conflicting rules, vague tone requests, and context overload) and how to fix them.
• If you reuse prompts across tools, saving instruction templates in CopyCharm can help you quickly find and paste the right version into Gemini.

Learn how to write Gemini custom instructions that reliably shape tone, structure, and decision-making, plus copy-ready examples you can adapt in minutes.

What are Gemini custom instructions (and what they are not)?

Gemini custom instructions are persistent preferences you set so Gemini knows how you want it to respond across chats. Think of them as your default operating guidelines: writing style, formatting rules, how much detail to include, what questions to ask you first, and what constraints to follow.

They are not a guarantee that Gemini will always follow every rule perfectly. They also do not replace providing task-specific context in a prompt (like your audience, inputs, or constraints). Custom instructions work best as a stable baseline, while each prompt supplies the specifics of the current task.

Version note: Where and how you set custom instructions can vary by Gemini surface (web vs. mobile) and account type. The writing principles and examples below still apply even if the setting name or location differs.

How to give Gemini instructions that actually stick

If your goal is “Gemini, respond like me,” vague instructions like “be professional” or “be concise” leave too much room for interpretation. Use a structure that makes your preferences measurable.

A simple template you can reuse

• Role: Who Gemini should act as (editor, tutor, analyst, coach).
• Audience: Who the output is for (customer, manager, beginner, expert).
• Output format: Bullets, table, JSON, steps, headings, length range.
• Decision rules: What to prioritize (accuracy over speed, cite assumptions, ask clarifying questions when inputs are missing).
• Do / Don’t list: Specific behaviors to include and avoid.
• Interaction style: How to handle ambiguity (ask 1–3 questions first; otherwise proceed with stated assumptions).

Write instructions as constraints, not vibes

Replace “be concise” with something like:

• “Start with a 1-sentence answer, then 3–5 bullets. Keep total under ~180 words unless I ask for more.”

Replace “be helpful” with something like:

• “If my request is missing key inputs, ask up to 3 clarifying questions. If I don’t answer, proceed with reasonable assumptions and label them.”

Resolve conflicts before Gemini has to

Conflicting instructions are a common reason outputs feel inconsistent. Examples:

• “Be extremely detailed” + “Keep it under 100 words.”
• “Never ask questions” + “Ask clarifying questions when needed.”
• “Use a friendly tone” + “No small talk.”

Fix conflicts by adding a priority rule, such as: “If brevity conflicts with completeness, prioritize completeness and use headings.”

Gemini custom instructions: copy-and-paste examples

Use these as starting points. Replace bracketed text with your details. If Gemini supports separate fields (for example, “about you” vs. “how you want responses”), you can split the content accordingly; if not, keep it as one block.

Example 1: Professional writing assistant (email + docs)

Custom instructions:

• You are my writing assistant for business communication.
• Default tone: clear, confident, and direct. No hype.
• Start with the final answer first, then supporting details.
• When rewriting, preserve meaning and any numbers I provide.
• Output format:
  • Subject line (if email)
  • Message body in short paragraphs
  • Optional: 3 alternative phrasings for the key sentence
• If key context is missing (audience, goal, deadline), ask up to 3 questions.

Example 2: “Concise but not shallow” explainer

Custom instructions:

• Explain things for an intelligent non-expert.
• Structure every answer as:
  • 1-sentence summary
  • Key points (3–6 bullets)
  • Example (1 short example)
  • Next step (1 action I can take)
• Avoid filler, motivational language, and long introductions.
• If you use a term that might be unfamiliar, define it in 10–15 words.

Example 3: Tutor mode (math/science/CS)

Custom instructions:

• Act as a patient tutor.
• Before solving, restate the problem and list given information.
• Ask one clarifying question if the problem statement is ambiguous.
• Show steps, but keep each step to 1–2 lines.
• After the solution, include:
  • Common mistake to avoid
  • One quick practice question (no solution unless I ask)

Example 4: Coding assistant (practical, safe changes)

Custom instructions:

• You are my coding assistant.
• Ask for language, framework, and constraints if not provided.
• When proposing code changes:
  • Explain the approach in 3–5 bullets
  • Provide code in one block
  • List edge cases and how to test
• Prefer minimal diffs and readable code.
• If you are uncertain, say what you are assuming and why.

Example 5: Product manager / analyst (structured outputs)

Custom instructions:

• Act as a product analyst.
• When I ask for a plan or recommendation, include:
  • Goal
  • Constraints
  • Options (at least 2)
  • Trade-offs
  • Recommendation + rationale
  • Risks + mitigations
  • Next steps
• Use tables when comparing options.
• Do not invent metrics or results; label assumptions clearly.

Example 6: Job search assistant (resume + interview)

Custom instructions:

• Help me tailor resumes and prepare for interviews.
• When rewriting bullets, keep them truthful and specific to my input.
• Use action verbs and measurable impact when I provide numbers; do not add numbers I didn’t give.
• For interview prep, generate:
  • 5 likely questions
  • STAR-style outline answers
  • 1 follow-up question I should ask the interviewer

Example 7: Personal assistant (planning + decisions)

Custom instructions:

• Help me plan and make decisions with minimal back-and-forth.
• If I ask for a plan, propose a default plan and offer 2 alternatives.
• When you need missing info, ask at most 2 questions; otherwise proceed with assumptions.
• Use checklists and time estimates as ranges (not exact promises).

How to refine your Gemini custom instructions (a quick iteration loop)

Step 1: Start with one job-to-be-done

Pick the main reason you use Gemini (writing, studying, coding, planning). Add only the rules that matter for that job. Overloading instructions can create conflicts and unpredictable outputs.

Step 2: Add one formatting rule you can verify

Examples: “Use headings,” “Return a table,” “End with next steps,” or “Include a short example.” If you can’t tell whether Gemini followed the instruction, it is hard to improve it.

Step 3: Add a clarifying-question policy

This is one of the highest-leverage instruction types. Decide whether you want Gemini to ask questions first or proceed with assumptions. Either can work; the key is being explicit.

Step 4: Keep a short “don’t do” list

Examples: “Don’t be salesy,” “Don’t repeat my prompt,” “Don’t add facts I didn’t provide,” “Don’t include emojis.” A short list is easier to follow than a long one.

Step 5: Test with 3 representative prompts

Use prompts you actually run weekly. If the output misses the mark, adjust one instruction at a time so you know what caused the change.

Common limitations and gotchas

• Instructions can be overridden by the task prompt. If your prompt asks for something that conflicts with your defaults, Gemini may follow the prompt.
• Vague tone requests drift. “Friendly” can mean many things. Add concrete constraints (sentence length, banned phrases, structure).
• Too many rules can reduce quality. If you stack many constraints, Gemini may satisfy formatting while missing substance. Keep the baseline lean.
• Account and surface differences exist. Some Gemini experiences may expose different customization controls. If you cannot find a setting, use a “pinned” starter prompt as a workaround.

Practical workaround: a “starter prompt” when custom instructions are limited

If you cannot rely on persistent custom instructions (or you switch accounts/devices), create a reusable starter prompt you paste at the top of a new chat. Keep it short and structured, for example:

• Role: You are my writing assistant.
• Output: 1-sentence answer + 5 bullets + example.
• Rules: Ask up to 2 clarifying questions if needed; otherwise proceed with assumptions labeled “Assumptions.”

Saving and reusing instruction templates with CopyCharm (especially across tools)

If you iterate on Gemini custom instructions, you will likely end up with multiple versions: a “short” one for quick chats, a “strict format” one for work, and a “tutor” one for learning. Keeping those variants somewhere you can quickly search and reuse can reduce repeated rewriting.

CopyCharm is a Windows desktop app that saves copied text locally, lets you search past clips, favorite important clips, and separately save reusable prompts. A practical workflow for Gemini looks like this:

• Save: Copy your best-performing Gemini instruction block (or starter prompt) and save it as a reusable prompt in CopyCharm. Keep separate prompts for “Work writing,” “Coding,” and “Tutor mode.”
• Find: When you start a new Gemini chat or switch tasks, search in CopyCharm for the version you want (for example, “gemini concise bullets” or “gemini tutor steps”).
• Reuse: Copy the saved prompt and paste it into Gemini as your starter message, or paste only the parts you need (like the output format rules).

This is a manual cross-tool reuse workflow for Gemini: you retrieve the text in CopyCharm and copy/paste it into Gemini. (CopyCharm has an authenticated connector for ChatGPT after eligible account authorization and AI Access sync, but that connector does not apply to Gemini.)

Try CopyCharm for saving and reusing prompt templates

Frequently Asked Questions

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