I'll look through a script, and if there's a lot of night shooting I tend not to want to do it. If there's huge party scenes and I'll go through a few pages and say "Well, at least I'm not in this," then the last page my character walks in and says something, I say, "Uh oh, that's going to be three days on the set sitting around drinking coffee at the craft-service table." Unless it's a great part. All in all if it's a great part you'll do it and I'll say, "Well, I'm gonna be on the set for three days."