My main advice would be don't take it for more than it is. Just a test, not the end all be all of the world. Being nervous during the test doesn't help you in any way, shape or form.
I'd also advise taking it easy the day before the test. I tried studying, and it became obvious that it wasn't going to help, and I was glad I could take a bit of a break and just kind of rest for a bit. Of course, this isn't good advice for everyone.