Caine had a piece of advice on physical technique that has always stuck with me, with respect to scene partners: Don?t change eyes. Look into one eye, and the eye that is closest to camera.
I think finding some kind of actor ?business? -- physical behavior that you can literally do -- is helpful. There?s the line of thinking that that kind of dimension can make your performance and character seem more ?real?, and all that. But I think, also, it keeps you from just ?parking and barking?, which can fall very flat. Also, it can keep you from gesticulating. Then again, I once had to swallow a pill during a scene (a prop pill -- a half-peanut), and was so nervous that I fumbled getting the aspirin bottle open, and even then, couldn?t manage to swallow the peanut once it was in my mouth. The ?pill? was still on my tongue when we hit my cue, and I just started chewing it, as a reflex. :)
Oh, and I have another one for you: I was offered a smaller-supporting part by a director friend, and I took the role without having read the play, or knowing much about my role or the cast, or any of that. So I read the play and discover that I am playing the love-interest/fiancé. So, okay. And it?s actually a pretty nice part. So, fine. So, I go to the first rehearsal and discover that the girl I have been cast with is very, very attractive. And as I?m looking through my part again, I realize that we will actually have an on-stage kiss. This acting thing might work out, I think. But the thing was, as we got closer and closer to that kiss -- the whole cast is just going through a table-read, but up on our feet, blocking things out -- I began to get extremely nervous. It began to feel like, it was my actual first kiss. I had something like stage-fright, times-two. And so I?m trying to subdue that, and rationally think my way through it. Be professional. And pages are rolling by at warp speed as we approach the moment. And so we get to the magic page, the line is approaching, I?m getting ready, the director stands up, the blocking is changed and the beat is dropped. Goodbye, kiss. :)