When I was a younger actor, I would try to keep it serious all day. But I have found, later on, that the lighter I am about things when I'm going to do a big scene that's dramatic and takes a lot out of you, the better off I am when I come to it.
Making a film is so hard that if you don't have your main actors going along with the ride with the rest of the crew it can make your life very difficult.
Part of the work is determining through what instrument you are playing. Actors are physical, olympian storytellers and we should be able to create entire landscapes with nothing.
Everyone is sort of in their own little area counting lines and no one talks when film's not rolling. There's constantly actors coming to me back behind the monitor screaming at me, "Why did my line count drop?" It's a nasty tense environment.