Very simply jobs are generally all different. I like to quote them specific to the clients expectations. An all day commercial job will be priced differently than a corporate headshot or family session.
Most importantly I want to know what their objectives and goals are. That will ensure success and happiness all around. Also it allows me to be better prepared for the photo shoot.
I have been a photographer for over 25 years. I keep up with the latest photography trends, including cameras and software. I teach photography and how to use software (photoshop, lightroom) at a college level.