I'm also a portrait photographer and have been for a long time. I'm certainly not going to give you any advice but I will make a couple of points.
1. I usually try to consult with my clients before the sitting to see them and come up with some interesting ideas. However often I get these ideas during the sitting and if the clothes etc aren't what I visualize then I will suggest we do some other pictures on a different day. No sitting fee.
2. I will make myself assignments and arrange to photograph people I pick, to work on some sort of project. I will approach people I see and explain that I would like to photograph them.
3. I've never really understood the way people seem to need to get into a gallery. If you have great portraits that you want to sell is there no other ways like the internet, designers, etc who would be interested in buying them. Plus there are the gallery type politics and commissions etc. Not for me.
I really think that if we do the first two points I made, then we have the best of both worlds. A client base that pays us to do what we like to do and also a ready made batch of models to do the stuff that we dream up. Seem perfect to me.