Throughout my time working with clients I always get the questions...
- What should I wear?
- How should I stand?
- What makeup should I use?
- Where should we take the photos?
It's somewhat intimidating to have photos taken, but the best thing you can do for yourself is simply be yourself. Don't try to be something you're not. Don't wear more makeup than you usually do. (But if you have some concealer on hand it's always great to cover up the shine). Wear the clothes that you feel most powerful and comfortable in. It will be represented in the images. Don't worry to much on how to stand or act in front of the camera. A great photographer will put you to ease and let you know exactly what you should do. There are little tricks photographers can do to slim you, cut down that double chin, and make your skin super smooth just with lighting.
As far as where the photos should be I always talk to my clients to better understand what they are trying to represent. If you are a CEO of a manufacturing corporation do you want to have a very formal corporate headshot? Most likely you don't. You want to be on a similar level to your customer and not over dress your representation.
The bottom line is, be you and let the photographer talk you through it. It's very painless and a great photo can speak volumes on your personality and character.