Acting and auditioning are very different animals. They require the same ingredients but in entirely different proportions.
Learning how to act in an audition is like a fighter learning how to fight in the ring. Not the best idea. One of the main differences between acting and auditioning is: Auditioning requires you to play the essence of the physicality. Which we as actors fall into the physical trap. Some of the most common ones are not having a moment before or moment after. Not wanting to move for fear of being to big, thus making yourself stiff and lifeless. My all time favorite is kissing. Auditioning for a part that requires kissing is difficult, my favorite mistake is watching people “air kiss” or “air make-out” extremely funny, extremely wrong. For this I will suggest that you do not “air kiss”, rather play the essence of the moment. Which is to feel passion, intimacy and love. Focus on feeling those elements and people will get what is going on. People will sense it, which is one of the beauties of acting.
Simon Longmore
Freeactingtips.net