Models follow instructions best when those instructions are clear, specific and consistent.
Be Precise
Vague words like "short", "detailed" or "professional" mean different things to different readers. Quantify: "under 120 words", "three bullet points", "formal but not stiff — no slang, no jargon".
Say What to Do
Positive instructions work better than prohibitions. "Write in short paragraphs of two or three sentences" beats "Don't write long paragraphs".
One Instruction per Idea
Break long compound instructions into a list. Numbered steps help for procedures.
Prioritise
When instructions might conflict — brevity versus completeness — say which wins.
Be Consistent
Use the same terms throughout. If you call something a "ticket" in one place and a "case" in another, the model may treat them differently.
Separate Instructions From Data
Put materials inside clear delimiters (tags or headed sections) so the model doesn't confuse content with instructions.
Provide Defaults for Edge Cases
Tell the model what to do when input is empty, off-topic, ambiguous or in another language.
Check Understanding
For complex tasks, ask the model to restate the task before doing it, or test instructions on varied inputs to find misunderstandings.