On of the funnest* things you can do with off-camera flash is to modify the light. This might mean squirting it through a “snoot” (some kind of tube or cone which focuses the light into a tight beam), reflecting it from a colored, uh, reflector, or firing it through a giant soft-box.
Or you can use a grid spot, an excellent tool for pointing your light at one single spot, far away, with a sharp fall-off into shadows at the edges. Sound expensive? It can be, unless you steal some drinking straws from your local fast food emporium and follow along with this how-to..