They never go exactly as planned. They're either a complete and utter failure -- worse than you could ever imagine, or they're so much better than you ever expected. My audition two days ago was the latter type. Thank goodness.
Some tips I find that help me come audition time:
1. Practice. And not just by yourself. Practice singing/acting/playing in front of people. First, make it people you know well. Your instructor, of course, as well as your family and friends. Then ask if they can recruit some strangers to come and watch you for a few minutes. See if you can get someone who knows a lot about what you're auditioning for, someone who can give you some ways to improve. But even if your audience knows nothing about opera or golf or whatever, it will get you comfortable performing in front of people. That way your judges will be nothing more than just more people you get to perform in front of.
2. Drink water. It doesn't matter what you're planning on doing, water is a refreshing way to make you feel better. It is the cure-all solvent, cleans out your body.
3. Dress your personal best... the way you feel most comfortable. This was something my voice teacher told me. She said to do your hair the way you feel a diva would wear it. Wear shoes that make you feel like queen of the world. Wear your favorite tie. Dress to impress... yourself. You'll feel better about yourself if you're not fidgeting with a shirt you never wear or pulling on tights. The judges only REALLY care about if you came prepared... you don't have to wear a skirt if you don't want to. Just as long as you're dressed confidently and intentionally with something that maes you feel comfortable.
4. Get there early. You might get to see how other people do on their auditions. You can learn from them, just as people after you can learn from you.
5. Make friends with some other auditioners. I know it's hard to see them as nothing more than competition; you may feel like you're fraternizing with the enemy. But try to remember that they're probably just as scared as you are. You're all in this together. If you get to watch them perform, focus more on just enjoying their performance. That will calm you down, cheering for someone else.
6. Your body reacts to stress. For me, I shake. Really bad. My legs were like jelly, even though I felt like my brain was totally focused and relaxed. Sometimes you just can't help it. But taking deep breaths and focusing just on what you are doing -- as if no one were watching -- is what's important when you're up there on the stage auditioning.
7. No matter how the audition goes, don't dwell on it afterward. Just relax; do something you love; don't allow your mind to think of the things you could have done or what the judges may be thinking. That's not important. What's done is done. Youc an only move forward.