At first, I charged a low per-session fee and tried to make money selling prints and digital rights on a per-image basis. But really, I don't like that model at all (neither did my customers) so now I charge a higher session fee and personal use rights to the images are included, in full resolution.
Most people don't realize how much time is spent in post-production. I spend hours re-touching. Not to mention, the time it takes to learn things like off-camera lighting and the cost of the gear associated. But, I'm not complaining, it's fun to learn.
I don't really profit from photography but it does cover some of the cost of my gear and it's just plain fun to do. Trying to make a living with photography would be extremely difficult, but clearly some people are able to pull it off.