|Sony 70-200mm - A light face with a darker background [click to enlarge]|
In most posed, natural light portraits I don't want any elements competing with the face for attention. I usually work to keep the face the lightest element in a dark environment, or the darkest element in a lighter scene.
Once I know that the environment will be darker than the face of the subject, for example, then the clothes should also be darker. More skin in the frame can draw the focus away from the face, so I strongly advise against short-sleeved shirts, or shorts. Other distractions, such as patterns, logos, text or stripes should be similarly avoided. All this means knowing or scouting the locations and having prior discussions with the subjects about clothes.
This seems a simple recipe, but sometimes there are complications. For example, a light face may be accompanied by dark hair; and that hair appears to blend into the similarly dark background. In colour portraits the hair can, sometimes, be distinguished against a different background colour. That, however, is not so easy when working in black and white. I'm lucky with the silver hair in the picture above.
This is, of course, all about posed shoots. In "street portraits" it's a "come-as-you-are party." While I try to be aware of backgrounds, and I try to get a brief pose (at least ask them not to smile), I have to take the best of what I can get.