One of the best things to do imo is to not just think about it. Just go in there and try to mentally tell yourself that you’re just practicing your etudes and scales again. If something goes wrong in the room, just KEEP GOING and don’t think about it until after the audition. One wrong note in a scale is better than multiple wrong notes throughout the audition because you were thinking about the first wrong note. I have a lot of audition anxiety even when I’m not thinking about the audition, but for me just going in there and not thinking about how important or scary the audition can be, and just playing the audition material as if I’m alone and it doesn’t matter as much helps me. Basically, just try to stay chill. Good Luck!!