RE: How do you guys stay calm??
When I first see the deer and decide to shoot I mentally prepare myself. I clip on my release, pick my shooting lane, get in position to draw. I then repeat to myself: "pick a spot, draw, anchor, stay locked on the spot, squeeze, follow through" If I get particularly rattled (rarely happenes now) I repeat to myself that I've made this shot thousands of times before on the 3d range, and in the back yard.
Also, in the offseason, I will do a 100 yard sprint, then go shoot one arrow. This very closely resembles the breathing and heart rate when you have a deer come in that you want to take.