Say what you want precisely
Audience, format, length, tone, and what to leave out. Most disappointing output comes from an instruction a careful human would also have found ambiguous.
Show, do not describe
One or two worked examples outperform a paragraph describing the style. This is the highest-leverage change available in most prompts.
Version them like code
Prompts drift, get edited in production and quietly regress. Keep them in version control with a small set of test cases you can re-run.
