An audition is the time that you want to shine and be your best. You want to make this audition seem like it's the most important thing, and, actually for the moment, it is!The first thing you need to do is what any other athlete does - look after and nurture your own body. You don't want to spend the night before an audition out drinking with your friends. You want to relax and get a good nights sleep. You may want to consider a relaxing massage the day before.
On a daily basis eat a healthy diet, get proper rest and make time to relax. If you learn meditation and practice it, it will help reduce the stress of every day too. Keep your body in tip top physical shape by continuing with your regular exercise routine. You may want to pay more attention to your physical appearance right before an audition - refresh that hair cut or color.
A lot of choreographers have started out right where you are today, in the chorus line. As dance is such a creative endeavor most choreographers depend on their gut instincts when they pick music, and dancers. They're looking at you from the minute you talk in the door. They want to see how you are interacting with others. How confident do you appear? Have you smiled? How relaxed do you look?