USA Today article entitiled "Photographers fight back against "Uncle Bob" explains the benefits of using a professional photographer. Professionals are trained in best lighting techniques, posing, eliciting good expressions, and so much more.
For example, when you book a photo shoot with Jill Lesly Jones, you receive a booklet that shows you how to look and feel your best in a photo shoot.
Here's a page on what not to do. For what to do, wear, makeup, pose and more, visit the contact page at this website.
Why a professional photographer is better than "Uncle Bob."