I can highly recommend that stiff drink before walking in the ring Bec & Newfie. Also if the trial was on a Saturday my last training session was on a Wednesday, done off territory with a friend acting the roll of judge. I didn't over warm up the dog immediately before going in the ring, just one quick heeling exercise with maybe a sit or drop so all up the warm up was about 20 seconds long.
I also found stewarding a few times before entering a trial made me much more at ease when I actually competed. And something a friend told me - they are 'a judge' not "The Judge".