Create Your Custom AI Assistant: The Complete Guide to Custom Instructions & Settings

2026/07/20·9 min read·82 views

Every time you talk to AI, do you have to repeat your needs? Every time you have to say "Please use plain language," "Please answer in Chinese," "I work in e-commerce"? Actually, you only need to set it once, and AI will remember it forever. This article teaches you how to use the "Custom Instructions" feature to create an AI assistant that truly belongs to you—it understands your background, knows your preferred answering style, and every conversation flows as smoothly as chatting with an old friend.

What Are Custom Instructions

Simply put, custom instructions are a "self-introduction"—you tell AI some information about yourself and your expectations for the answers, and AI will automatically apply these settings in every conversation.

For example: You are a new e-commerce seller, and every day you ask AI about product copy, customer replies, and marketing strategies. Without custom instructions, you have to say each time "I am in e-commerce, please answer in simple and easy-to-understand language." With custom instructions, AI already knows who you are and just gives the answer directly.

Currently, mainstream platforms that support custom instructions:

ChatGPT: The most mature custom instruction system, supporting two dimensions: "About You" and "How You Want to Be Answered"
Claude: Achieves a similar effect through the Projects feature, allowing you to set project-level instructions
Doubao: Supports creating "AI Agents" to achieve personalization through role settings
DeepSeek: Supports system prompt settings
Tongyi Qianwen: Supports custom roles and instructions

Four Steps to Create Your Exclusive Assistant

Four-step process for custom AI assistant

Step 1: Choose Your Platform

Different platforms have different setup entry points, but the principle is the same. Below are the setup paths for each platform:

Setup Entry Quick Reference

ChatGPT	Settings → Personalization → Custom Instructions
Claude	Projects → New Project → Set Instructions
Doubao	Discover → Create AI Agent → Role Setting
DeepSeek	Chat Interface → System Prompt Icon
Tongyi Qianwen	Toolbox → Custom Roles

Step 2: Tell AI Who You Are

This is the first part of custom instructions—"About You." You need to tell AI the following information:

Your identity: What do you do? (e.g., e-commerce seller, college student, programmer, mom)
Your level: How much do you know about this field? (zero basis / some experience / professional)
Your needs: What kind of questions do you most often ask AI?
Language preference: What language do you want AI to answer in?

Example: I am a new e-commerce seller, mainly selling home goods. I know nothing about AI and programming, please answer my questions in the simplest language possible. I want practical advice, not theoretical knowledge.

Step 3: Set the Answering Style

This is the second part of custom instructions—"How You Want to Be Answered." You can control AI's answering style:

Language style: Formal / Plain / Humorous / Professional
Answer length: Short and direct / Detailed explanation / Adjust as needed
Include examples: Whether you want AI to include specific examples in the answer
Format preference: Like lists / like paragraphs / like step-by-step
Special requirements: For example, "Please mark uncertain content"

Example: Please answer in plain and easy-to-understand Chinese, avoid technical jargon. Give specific steps for each suggestion. If numbers or data are involved, present them in a table. Keep answers within 300 words, unless I ask for a detailed explanation.

Step 4: Test and Optimize

After setting up, don't rush to use it. First test the effect with a few questions:

Ask a question you often ask and see if the answer meets expectations
If the answer is too professional, add "Please avoid using technical terms"
If the answer is too long, add "Keep answers within 200 words"
If the answer is too vague, add "Please give specific steps"
Adjust repeatedly until you are satisfied

Tip: Custom instructions are not a one-time fix. As your needs change, remember to come back and update the instructions. It is recommended to check once a month to see if adjustments are needed.

5 Practical Templates, Copy and Use Directly

Below are 5 custom instruction templates for different scenarios. You can copy them directly into your AI platform.

Template 1: E-commerce Seller Assistant

You are an e-commerce operations consultant, focusing on the daily operations of small and medium sellers. I am a new seller, mainly selling home goods on Taobao/Pinduoduo platforms.

Please answer in plain and easy-to-understand Chinese, avoid technical terms. Each suggestion should include specific steps, preferably ready to copy and use. Keep answers within 300 words.

Special focus: product copywriting, customer scripts, marketing campaign planning.

Template 2: Learning Tutor

You are a patient tutor, targeting college students self-learning programming. My foundation is some Python, but I am not familiar with data structures and algorithms.

When explaining, use analogies from daily life to illustrate abstract concepts. Provide a small runnable example for each knowledge point. If I make a mistake, first point out the problem, then give correction suggestions.

Answer format: First summarize the key point in one sentence, then explain in detail.

Template 3: Content Creator Assistant

You are a self-media content planner, skilled in content creation for Xiaohongshu, Douyin, and WeChat public accounts. I am a personal blogger, mainly sharing career growth and productivity tools.

When writing copy for me, please note: titles should be attractive but not clickbait; the body should be easy to understand and fun, using short sentences; the ending should include an interactive call to action. If I give you a topic, first provide 3 titles from different angles for me to choose from.

Template 4: Fitness and Diet Consultant

You are a fitness and diet planner. I am an office worker, sitting for more than 8 hours a day, wanting to lose fat and gain muscle but have no fitness foundation. I can exercise 3 times a week, 45 minutes each time.

Please give specific, actionable advice, not vague theories. For training moves, specify sets, reps, and rest time. For diet advice, give specific dishes and portions. Considering my busy work schedule, prioritize simple and easy-to-follow plans.

Template 5: Writing Polishing Assistant

You are a Chinese writing polisher. When I send you a piece of text, please help me: 1) Correct grammar and wording errors; 2) Make the expression more fluent and natural; 3) Keep the original meaning and style unchanged.

After polishing, mark the changes you made and briefly explain why. If the original text has no obvious issues, just say "Well written, no need to modify." Do not over-polish; keep the style plain and natural.

Detailed Setup Tutorials for Each Platform

ChatGPT Setup Method

ChatGPT's custom instructions feature is the most complete; set it once, and all conversations automatically take effect.

Open ChatGPT, click your avatar in the bottom left corner
Select "Settings"
Click the "Personalization" tab
Find "Custom Instructions" and click to enable
You will see two input boxes:
- First box: "What would you like ChatGPT to know about you to provide better responses?" — Fill in your identity, background, needs
- Second box: "How would you like ChatGPT to respond?" — Fill in answering style, format, length, etc.
After filling, click Save
Start a new conversation to test the effect

Advanced Tip: ChatGPT also supports the "Memory" feature, which automatically remembers preferences you mention in conversations. You can manage these memories in settings, deleting unnecessary ones and keeping useful ones.

Claude Setup Method

Claude achieves a similar effect through the Projects feature:

Open Claude, click "Projects" on the left
Click "Create Project"
Give the project a name (e.g., "My E-commerce Assistant")
In the project settings, find "Project Instructions"
Paste your custom instructions
From now on, all conversations under this project will automatically apply these instructions

Doubao Setup Method

Doubao achieves personalization by creating an "AI Agent":

Open the Doubao app or web version
Click the "Discover" tab at the bottom
Find "Create AI Agent" or "Create Bot"
Fill in the agent's name, description, and role setting
In "Role Setting", paste your custom instructions
Choose an avatar and click Create
From now on, talk directly to this AI agent

6 Tips to Make Instructions More Effective

1. Clearly state who you are, not just what you want

Don't just write "Please use simple language," but write "I am an AI novice, completely unfamiliar with technology, please use the simplest language." Background information helps AI better adjust the depth of the answer.

2. Give specific constraints, not vague expectations

"The answer should be good" is not a good instruction. "Keep answers within 300 words, use list format, and match each point with an example" is better.

3. State what you don't need

Negative constraints are equally important. For example, "Do not use technical terms," "Do not give theoretical analysis, only practical steps," "Do not start the answer with 'Okay' or 'Sure'."

4. Set only one role at a time

Don't make AI simultaneously act as a teacher, lawyer, doctor, and psychologist in one instruction. If you have different needs, create different AI agents or projects and set them separately.

5. Update your instructions regularly

Your needs will change. It is recommended to check your custom instructions once a month, delete content you no longer need, and add new requirements.

6. "Train" AI through conversation

In addition to custom instructions, you can also continuously adjust AI's responses during conversations. For example, "This answer is too long, please be shorter in the future" or "This example is great, use more of this style in the future." AI will gradually adapt to your preferences.

Frequently Asked Questions

Will custom instructions affect all conversations?

Yes, on most platforms, custom instructions take effect globally. This means every conversation you have with AI will apply these settings. If you need different styles, you can create multiple AI agents (Doubao) or projects (Claude) to manage them separately.

Is there a character limit for custom instructions?

Different platforms have different limits. ChatGPT has about 1500 characters per box, Claude's project instructions are longer. Generally, concise and clear instructions work best; you don't need to write too long.

Can AI still switch styles after setting custom instructions?

Yes. Custom instructions are the "default settings," and you can override them anytime in a conversation. For example, you set "Please answer in plain language," but for a specific query you can say "Please explain this using technical terms," and AI will follow the current conversation's request.

Can free-tier users use custom instructions?

Yes. The free versions of ChatGPT, Doubao, and DeepSeek all support custom instructions. This is a basic personalization feature that does not require payment.

What is the difference between custom instructions and system prompts?

Custom instructions are a visual settings interface for ordinary users; system prompts are a developer-oriented method set via API. For ordinary users, custom instructions are sufficient and there is no need to understand system prompts.

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