Some pretty good tips here but I haven't see any of the stuff that helps me. I'm pretty new to flying but picked it up right away. Now I do lots of maiden flights, tuning flights and buddy box stuff, too. Sometimes I just stand next to people and that helps them stay calm. I always ask for a second set of eyes to stand next to me on a maiden or tuning flight. It helps to have the extra eyes and that way I don't seem crazy when I talk to myself.
When someone hands me their controls for a new plane or I have something new that I'm going to fly. I jump around a bit, raise my arms, shake my hands and do a little dance to get the blood pumping. Occasionally will yell Kick me in the Jimmy! (Beavis and Butthead, anyone?). Not only does it get my psyched up but also lightens the mood. I think it's that combination that helps me.