Actually thinking about it I have quite an extensive ritual:
1) I go to the loo 5mins before (mainly to be on my own for a bit) I wash my hands thoroughly.
2) I slowly walk back psyching myself up "I'm ready" "let's do this" etc. I keep my fingers separate so as not to get hot.
3) I walk in, hand in my phone, wish friends good luck and make a mental note of where I put my bag.
4) Try to find my seat as quickly as possible, put my water bottle underneath.
5) Take out my stationary (1 of each thing), nicely lay it out.
6) I scribble to check my black pen works.
7) Do 2+2 on my calculator, crap myself at this point if I get anything but 4.
8) I write my name and details before being told too (one exam they gave us no time for this!) and always in lower case, have a complete mental block on doing upper case but haven't failed an exam for it yet!
9) Take a swig of water.
10) Blow on hands to keep cool.
11) Turn over the page instantly to give myself maximum time and scan my eyes to the first question.
12) Cry