If you want to up the drama in a portrait, choose the split lighting pattern. Split lighting reveals one half of the face in light while leaving the other in shadow. It’s achieved by moving the light still lower and around to the side of the head—roughly 90º from the direction the nose is pointing and about on par with eye level. Feathering the light slightly in front of the subject will help to avoid a hot spot on the side of the face, and a slightly forward source may also make for a more attractive split, as it can allow a hint of light to spill onto the lit-side eye, which is much more appealing than having both eyes in shadow (which will happen if the light is too far back).
Split lighting is a great way to slim a large subject, particularly against a dark background, where the shadow side can all but disappear into the darkness. It also brings out every texture on the face and adds mystery and drama; whether these are problems or benefits depends entirely on the subject.