During the Headshot Marathon, I had an amazing shoot with an experienced DC actor, Don Mike. He hosts a music event every Thursday at the Black Fox Lounge, something which you all should definitely check out. While we only had two looks to work with, we absolutely nailed it. He was fun to work with and very professional about the whole process.
Be careful if you're wearing glasses at a shoot; if they're not anti-glare, they could pose a problem with all the lights that could reflect back off of them.
BE YOURSELF! Don't overdue makeup or anything that will make you look less like your true self. In the end, it's better to go natural than to walk into an audition and be unrecognizable from your headshot. Wow them with your talent, not with smoke and mirrors.