Make sure to expect the unexpected during an audition. A ringing cell phone or sudden outside noises shouldn't shake you out of your performance. Shake off distractions by pouring your entire being into the part and try to enjoy yourself.
Think of the audition not as a necessary evil, but as a performance for a much smaller audience. Enjoy auditioning as you would a small theater performance. Try not to see the audition panel as a group looking to criticize your every move. During your audition, don't worry that you may be outside their parameters for the part and just focus on staying in character or on key.
Use material you are confident and experienced with. The more you know the material, the calmer you will be during the audition. Do not use newly written monologues or songs you hardly know, otherwise you may be more nervous about making mistakes. If you have any questions about the material, don't be shy about asking the panel.
Take deep breaths after entering the audition space and before stepping onto center stage. Do not rush onto the stage, but enter calmly. Introduce yourself and your auditioning piece with confidence. Inhale and exhale completely. Concentrate on keeping nervous tics to a minimum, such as fidgeting or moving around. Close your eyes and visualize the best performance you can give.