Yes, like posted above, take of yourself. Get up early. (I had to be up by 4:30 to drive to my center)
Start thinking what you will pack for lunch/snacks. (I think it helped to eat what I was going to eat on the AAMC scored.)
Visit the testing center. Mine was extremely hot and the proctors were assholes.
Prepare yourself, don't do anything crazy. You can breeze through the questions you got wrong and reason through them.