How do you stop yourself from writing paragraphs when a single bullet point will do?

Working with busy people taught me a hard lesson nobody has the time to read your backstory. I used to spend twenty minutes crafting the "perfect" email flow only to get a single-word reply back. At first it felt kind of rude, but then I realized they were just respecting my time by keeping it brief. Now I try to put the main ask right at the very top so there's zero guesswork.

What's your personal rule for keeping messages short without sounding abrupt or rude?