Audition, Audition, Audition
An actor's job is auditioning. Work is the bonus! Over the years I've heard actors say "I'm not a good auditioner," which I understand. It's a false situation, acting opposite yourself (essentially) in a foreign environment not related to your character or his/her situaiton. However, in order to get to the next level, you must master the art of auditioning.
I believe in audition practice. Go on as many auditions as possible. Student film? Sure? Short? Why not! That way, auditioning becomes an every day event for you. You may not be as nervous when the big one comes up!
Tape yourself. Auditions are 99% taped and re-watched later. Know your relationship with the camera & rid yourself of any odd inauthentic movements BEFORE you walk into the room. It may feel foreign at first, but ultimately incredibly beneficial.
Do not apologize in the audition room. It may sound elementary, but you'd be shocked how many versions of apologies we get. "I'm sorry, I messed up - may I begin again?" "I'm sorry, this is not how I rehearsed it" "I'm sorry, I'm going through something right now." We are not unsympathetic, however how actors DEAL with their mistakes is key. Also, odds are we didn't notice because we don't rehearse with you. Whatever you present on the day is the only thing we see! Remeber process vs. product
Say the words out loud many times before you enter ther room. Often times actors come in & haven't spoken before the audition. Rehearse. Rehearse your movements, thoughts, beats so you have the fundamentals to fall back on.
And finally, have fun. Auditions are opportunities not only to possibly book a job, but to meet with someone new. Show your fun, unique personality & make an impression with you.