Meet Giovanni. He's an actor I worked with on an 1930's Gangster Shoot I organized last year. He moved out to LA a week ago to further his acting career, but before he left, he asked me to shoot headshots for his portfolio.
Most of the light in this image is natural and coming from camera right (Giovanni's left). It's gorgeous light that makes for great shadows and wonderful "catch lights" in the subject's eyes. The highlights in Giovanni's hair and the left side of his face are coming from a small flash I placed to camera right. That's the "wink of light" that helps separate Giovanni's hair from the dark background. It also highlighted the left side of his face giving it shape and depth.