The standard size is an 8-by-10-inch glossy print with a close-up on your face. Headshots for models are sized 9 by 12. The photo should "bleed," or lack borders.
Commercial film and television headshots portray the subject from the shoulders up in a relaxed pose and direct lighting. Dramatic headshots use theatrical lighting and costumes to create mood and emotion. Finally, glamour headshots are appropriate for models, dancers and singers and for soap opera roles.
In the early 2000s, a trend toward color headshots began. Black-and-white headshots are still accepted, but have both types on hand.
Dress simply--black or white is suitable. Minimize jewelry; you don't want to take attention from your face. Your hair and eye color dictate background--be careful not to wash yourself out. Apply makeup at the studio so that you can make adjustments.
Search industry papers like "Backstage" or "Variety" to find a photographer. Professionals charge $50 to $2,000 a session.