'There's no such thing as writer's block. It's a myth. What you do is you sit down at a keyboard and you type a letter, and then you type some more letters, you have a word. Then you type some more words, you have a sentence. A few more sentences, you have a paragraph. What you write is better than you think, but what stops people is the self-editing, this little person in your head who keeps critiquing you. You got to kill that person, you just got to flick them off your shoulder, stomp on them 'til they're bloody. You have to sit down and write, and stop worrying whether people will like it. Just write for yourself.'
Alan Weiss's approach to writing is bracing. If you're getting bogged down in endless rewriting or self-critiquing, this is going to be uncomfortable listening. Uncomfortable, but essential.