New use for ChatGPT Custom Instructions: fix the tone and format of replies in one go

Many people have been discussing lately that ChatGPT’s replies can feel “a bit aggressive” or overly preachy. In fact, ChatGPT has a very practical feature: Custom Instructions. They let you lock in ChatGPT’s tone, structure, length, and default assumptions in advance, so each conversation fits your habits better. Below is the shortest path to explain how to enable it, how to write it, and how to avoid things going wrong.

What real pain points can ChatGPT Custom Instructions solve?

When you feel ChatGPT “likes to ask back, likes to judge, likes to moralize,” it’s often not that the model has gotten worse, but that when it’s uncertain it uses stronger wording to “stabilize the answer.” Custom Instructions are like giving ChatGPT a fixed set of communication guidelines: less fluff, conclusion first, and no condescending tone.

Another common pain point is inconsistent formatting: sometimes you get a checklist, sometimes you get an essay. Once you write the format into Custom Instructions, ChatGPT will output more consistently in the template you need—for example, key points first, then steps, and finally precautions.

Where to enable ChatGPT Custom Instructions (two steps)

On the ChatGPT web version or in the app, go to “Settings,” and find “Custom instructions.” The entry name may vary slightly across platforms, but it’s usually under your profile avatar/menu.

After you open it, you’ll see two input boxes: one for “What would you like ChatGPT to know about you?” and another for “How would you like ChatGPT to respond?” It’s recommended to focus on “How to respond,” because it directly determines ChatGPT’s tone and output structure.

Three ready-to-copy ChatGPT Custom Instructions templates

Template 1: No preaching, no sarcasm (general)
“Please answer in a friendly, restrained, non-judgmental tone. Do not use wording like ‘Let me correct you first’ or ‘You clearly…’. Do not mock or use irony. If information is insufficient, ask 1–3 brief questions to fill the gaps; don’t give a long lecture.”

Template 2: Conclusion first, details later (for efficiency)
“Use a fixed answer structure: ① one-sentence conclusion; ② a bullet list of 3–6 key points; ③ actionable steps (numbered in order); ④ risks/notes. Default to Chinese unless I request English. Keep it as short as possible and avoid empty talk.”

Template 3: Writing/material organization (more like an editor)
“You are a content editor. Provide titles, subheadings, and paragraph summaries. When citing viewpoints, note ‘possible source directions/keywords.’ Do not fabricate data or sources; if unsure, say you’re unsure and give verifiable search suggestions.”

The easiest pitfalls when using ChatGPT Custom Instructions

The first is writing too much and too detailed, which makes ChatGPT “recite rules” every time, causing answers to become slower and more rigid. Keep 3–5 core rules: tone, structure, length, and whether to ask questions before answering.

The second is turning factual requirements into “must be correct,” which won’t suddenly make ChatGPT an authoritative database. A more effective approach is to require ChatGPT to label uncertainty, provide a verification path, and ask clarifying questions when necessary—this makes outputs more stable and more usable.