Here is a short list of tips if you are looking to get some headshots taken and you are an author:
1. Come in a good mood to the session. Eat well and get enough rest.
2. Make sure your confidence shows in the shot. Whether you're serious or not, it doesn't matter. You still need confidence to show.
3. Don't always think about getting the perfect shot. Relax! The shot will come and as long a you tell the photographer what you need, he'll make sure to get it.
4. Determine beforehand if you want anything specific. Typically, author headshots are less static than business and lawyer headshots. You have many more options and can play with it. It always helps if you have an idea of what you want before the portrait session.
5. Have a good time, and relax!!