The most important thing to do in a head shot is look natural and be yourself. You don't want the producer to do a double-take when he sees you in real life, wondering if you really are the person in the photo. If your head shots do not look like you, you may be wasting your time auditioning for producers who are looking for a different type of person.
The clothes you wear in your head shot should be simple and understated. Do not dress up in costume, even if you are trying out for a role that would require one. Instead, appear neutral so that producers can use their imagination to turn you into the character you are auditioning to play.
Do not wear too much makeup. Allow the real you to show through. Pounds of makeup can act as a distraction from your natural good looks. Being overly made up in your head shot may prevent you from landing an audition.
Not only should your eyes be the focal point of the picture but also they should express your personality. Use your head shot to make a connection with whomever is viewing it. Emphasize a sincere look that allows you to come across as a genuine person. Do not force any facial expressions. A forced smile can ruin your head shot. Stick to poses and expressions that are natural for you and that you are comfortable with.