From Steven Pressfield on how to get started:
Have you ever asked a friend who’s an artist or entrepreneur how they’re doing on a project you know they’re psyched about? Sometimes you get the answer, “I’m getting ready to start on it.”
“I’m working up the outline.” “I’ve almost got the business plan.” “I’ve got a little more research to do.”
When Resistance hears phrases like that, it can hardly contain its glee. Resistance knows that the longer we noodle around “getting ready,” the more time and opportunity we’ll have to sabotage ourselves. Resistance loves it when we hesitate, when we over-prepare.
The answer: plunge in
Write a bad version 1 as fast as you can; rewrite it over and over; cut out everything unnecessary; write in a conversational tone; develop a nose for bad writing, so you can see and fix it in yours; imitate writers you like; if you can’t get started, tell someone what you plan to write about, then write down what you said; expect 80% of the ideas in an essay to happen after you start writing it, and 50% of those you start with to be wrong; be confident enough to cut; have friends you trust read your stuff and tell you which bits are confusing or drag; don’t (always) make detailed outlines; mull ideas over for a few days before writing; carry a small notebook or scrap paper with you;