I have a writer who is, for the large part, not lazy. But there are a few golden rules to getting his best:
1. Don't distract him with shiny things
2. If producing/filming what he's writing don't talk to him about frame rates, lighting, or ANY aspect of filming the script. It'll make him rethink that well-though-out scene with manic Bolivian girls (I really wish I was joking about this premise, but I'm not).
3. Although it's been said before, the sagely advice of the hour is to set a deadline. (Also imposing some arbitrary punishment for letting the aforementioned deadline to pass is both motivational and fun.)