As for my lighting set up, assuming you mean the low key stuff, it's really pretty simple. As you guessed, one light with a softbox, a snoot, grid or barn doors, depending on the specifics of the individual shot. The models are usually four to five feet from a black paper background, frequently with a gobo to keep light away from the background. In the forground, I either use the black paper, one of several black fabrics or just the hardwood floor. The 'secret' is precise placement of the light and shadow on the model, an inch can make a significant difference. It's routine for me to have the model move slightly forward and backward and turn from left to right whhile I watch what happens to the light and shadow and how it rreacts to the torso. But the major secret, no two torsos are the same and different skin reflects light differently!, that's major. When learning this technique, it very helpful to dim or even turn off ambient room light so the shadows can be seen more clearly. Meter the highlights!!!!!
As you can see in the attached, a lot of room isn't really necessary.
To show the light set up, I had the model move forward about a half step to get more light on her back.
