Portraiture is all about bringing out the character of your subject. This great video goes behind the scenes of a shoot, showing you how lighting was designed to match the intended portrayal of the subject and the resulting photos.
Coming to you from Joe McNally and Daniel Norton at Adorama TV, this great video follows them as they break down the way they'd like to portray the character of their model in a shoot and then sculpt the lighting to match, opting for soft, highly diffused light that reduces shadows and contrasts very nicely with the black background and wardrobe. The idea is essentially to wrap soft light around the subject in a relatively precise way that keeps the background black. Notice that they get some great natural separation from Mary's hair, while they use a v-flat to provide a subtle highlight on her arm to separate the black wardrobe from the black background. They also use a v-flat laid horizontally as a large bounce card to further reduce the shadows. The result is a light, yet still defined set of portraits that match the soft, elegant look they had envisioned and suit the character perfectly.