The Brooklyn College costume shop staff is asked this question quite often. "What should I wear to an audition?" The general consensus seems to be to wear clothing that best represents the character without looking like a costume. Outfits should be stylish, neat, clean, flattering and not too flashy. Stay away from black and white especially for on-camera auditions. Good grooming is a must (unless the character is a bum) and fresh, light make up is essential for women. Of course, for every rule there seems to be an exception! What you wear to audition for a laundry detergent commercial might not be what you wear to audition for Quentin Tarantino! To help answer your questions further, I've complied information below from a casting director and two blogs written by fellow actors.
Casting Director, Marci Liroff
From the blog, NYC Actor
From Unscripted Backstage
If you have questions about grooming, shopping or styling, make an appointment with the costume shop and we will be more than willing to give you some advice. BREAK A LEG!!