Popular Photography has a segment by Aaron Anderson on doing dramatic portraits with one light source. It’s actually a two-parter in that there’s a corresponding segment (bottom of their page) on the followup processing you need to do. Check it out; click with gusto my friends.
Basically, it’s a large soft box and reflector setup. But, what they’ve added is a black flag in the middle of the soft box configuration. It’s interesting.
In fairness, they talk about minimal gear but what they show are some pricey C-stands and the lighting and wireless triggers are not cheap. One can work around such things, though…maybe using CFL’s, an umbrella, and cheaper light stands.