Standard portraiture from the point of the photographer, often involves providing a lot of direction ... look this way, chin up, face towards me, hands in your lap, etc. But working with a model, especially an experienced model, can be relaxing and often is just downright fun! The main difference being that both of you have some concept as to what is involved in "creating the image".
I recently had the privilege of working with a model. While her needs for this photo shoot were simple (nothing more than a head shot or two), we still had a bit of fun playing with a couple of different styles. Below is a collage of several of the head shots we came up with during this session: