Nice going with portraits and hidden-halves, Daniel. : )
You'll get there with the balancing of the invisible and the visible parts in time. Good thing you have very patient and volunteering models. : ) Just keep shooting and one day you'll find that you'll decide within seconds on what the shot requires to be a little mystical and seductive or maybe innocent with similar shots.
A good concept. The girl and chess set looks best, because she is old enough for playing chess to fit in, as well as looking attractive and having the right pose and expression. I like the glass chess set, and it works much better than a regular set would.