This is a typical lighting setup for me "in the field". Mind you, I don't use studio strobes when I'm shooting around derilict factories and warehouses -- instead you'll usually find me carrying a Nikon SB-24 attached to a wireless receiver, usually sitting atop a lightweight stand. The light from this flash will be set just a notch or two higher than the ambient/environmental light, just to make the subject "pop" off of the darker background. The reflector on camera-right (the model's left) bounces some of the light from that same strobe back onto the dark side of the model's face/head, softening some of the shadows a bit. This is a must for most women, but with most guys, I can forgo this extra step. The black diffusion panel on camera left is usually played by a wall or other large object, but the point's the same -- keep light off the background. I can often forgo this step if there's significant distance between the subject and the background, or replace the baffle with something that has a unique shadow, adding a layer of interest to the shot. While only needing to use one ~actual~ strobe, this setup is a take-off on a traditional three-light setup used by most studio photographers. Note also that I'll occasionally place my flat-panel flash somewhere in the background, triggering off its optical slave, just to accent some element behind the model, again adding another layer of interest.