Since writing is very hard and rewriting is comparatively easy and rather fun, I always write my scripts all the way through as fast as I can, the first day, if possible, putting in crap jokes and pattern dialogue—“Homer, I don’t want you to do that.” “Then I won’t do it.” Then the next day, when I get up, the script’s been written. It’s lousy, but it’s a script. The hard part is done. It’s like a crappy little elf has snuck into my office and badly done all my work for me, and then left with a tip of his crappy hat. All I have to do from that point on is fix it. So I’ve taken a very hard job, writing, and turned it into an easy one, rewriting, overnight. I advise all writers to do their scripts and other writing this way.
Garnerphiles will have heard similar advice before.