ORIGINAL: Matt / PA
Joey are you looking for advice!?[:-]

LOL
"Hey guys, I've been just a little shaky on the last couple booner bucks I've shot, and I'm really striving to be solid and cool as ice when the next 180" walks by me......"
(jk)
I (believe it or not) have been in the prescence of some big bucks in NE and IL although I don't have any of them to show for it........

What I do mentally is EXPECT to see a big deer (or any deer) and plan for their approach, and how I will execute the shot. (cause that's working.

)
I think if you are surpised by the sight of a deer it jump starts that adrenaline and things can get a little foggy from that point. If you can keep that initial jolt down then things don't start going fast and slow at the same time.
When you identify an animal you want to take, I know it sounds cold but you have to no focus on turning those vitals into a target. Start focusing on a spot, think about where you will take the shot and make it happen.
I agree with Matt on this one, if you see the deer coming, you can prepare yourself and take a few deep breaths. Late season this year , I had a nice 6 surprise me out of now where and totally freaked out, missed the 30 yd shot low. Hoenestly, I love the feeling, I just like to have a little time to compose myself before shooting
Shane