1. Post-Production (Photoshopping)
Remember that the actor’s headshot should be you (and you as in current you, not a few years ago), so photoshopping or any editing should be extremely light. There’s no harm in removing those fly-away hairs – a good hairbrush would have done the same thing, but if you’ve gained a few pounds and want to look lighter, your photographer or editor should not be doing it for you. Your agency may reject any headshot that isn’t a true representation of who you are right now and the last thing you want is to attend a casting call where there’s a disconnect between your image on file and you in person.
2. Theatrical & Dramatic
Unless you specifically want a more theatrical or dramatic look, your headshot should be clear of heavy shadows and well lit generally. Some contrast, to show the shape of the face is fine (for example, a small nose shadow) but if half your face is in shadow, it might look great and impact-full, but it doesn’t give the casting director a clear idea of the shape of your face.
3. Be Someone
When your having your headshot taken, be expressive through your eyes, stance, and other small nuances. Remember, you want to show how well you can fit into a role, so, if it’s comedy, it’s OK be more positive than normal, the eyes may shrink a little, a few wrinkles might show, but it’s you.