One light with a black background. The model is facing the light at a 2/3rd angle. Delightful.
Still using one light the model was asked to look straight ahead to give a more dramatic image.
Here a red gel was placed on a light pointed towards the back of the head (hair light) and a "snoot" on another light was used to focus light on the face. Very mysterious.
This is an example of the photo above, but the "snoot" light was narrowed and focused on just the eyes -- Casablanca style.