There are a lot of opinions as to what a "head shot" should look like. Typically it's a head and shoulders shot with lighting coming from the top and from the bottom such that the face is lighted evenly. The person in the head shot is typically looking directly into the camera. Very little makeup is used and very little (if any) enhancement is made with Photoshop. This would be the type of head shot that might be requested by a model agency and should be something they could show to a potential client that shows what you really look like and what it might be like to work with you in a photo shoot, movie, or commercial. The agency already knows that you can look great with good makeup and with enhancements from Photoshop.
Your "head shot" may be more of a head shot that could be 3/4ths of your body or a full-body photo. It may be something casual with your head turned away from the camera. Tell me what YOU want the head shot to look like or what your agency has requested and I'll do