Use Percentages

Here is a little thing I saw years ago in an interview with Brian Singer when he made the first Xmen movie, I've applied it ever since and found it to be very useful. He was talking about what it was like directing a real professional veteran like Patric Stuart. Brian asked Patric to lift the emotion in a scene, he was surprised by the business like response from Patric, "how much more, 20%, 30% more?"

After Brian realised it was OK to talk to him about his craft in such a specific, calculating way he found it really easy to communicate what he wanted. Now I do the same thing whenever I am being directed or am directing.

That pose needs to lean in 20% more. . . . . . . . . . . . . That action should be about 40% slower. . . . . . . . . . . So you want that punch to have to hit 50% harder?. . . . . . . . . . . . So you want less emotion there, how much less? 10%? 20?

Clear, concise and to the point. You're happier because you know whats expected of you and your boss/teacher is happier because they feel its clear what is expected. Its so simple, but really helps me out in my day to day work.