Well, let’s start with the maxim that the best writing is understated, meaning it’s not full of flourishes and semaphores and tap dancing and vocabulary dumps that get in the way of the story you are telling. Once you accept that, what are you left with? You are left with the story you are telling.
The story you are telling is only as good as the information in it: things you elicit, or things you observe, that make a narrative come alive; things that support your point not just through assertion, but through example; quotes that don’t just convey information, but also personality.