The four parts of a good prompt
Role: who the model should be. 'You are a senior email marketer' changes the vocabulary, the structure and the level of assumed knowledge.
Context: the situation the output has to fit. Budget, audience, tone, constraints, what has already been tried.
Task: the actual deliverable, stated as concretely as possible. 'Write 5 subject lines under 50 characters' beats 'help me with marketing'.
Format: how the answer should be shaped. A table, a list, JSON, a 200-word draft, bullet points with sources.
Before and after
Weak: 'Write about productivity.' There is no audience, no angle, no length and no format, so the output will be generic filler.
Strong: 'You are a productivity coach writing for remote developers. Write 5 tactics for protecting deep work time, each with the tactic, why it works and a one-sentence implementation step. 400 words total, no bullet-point intros.'
The second prompt takes twenty seconds longer to write and produces something you can actually use.
Three habits that improve results
Give examples. Two or three samples of the style you want will do more than any amount of describing it.
Ask for the reasoning before the answer when accuracy matters. A model that shows its working is easier to check.
Iterate in place. Instead of starting over, say 'keep the structure, make the tone more direct, cut it to 150 words.'