Normally in portraiture, you get a high level of control over the lighting, but in some scenarios (weddings, for example), you will have to think, light, and shoot on your feet. This excellent video tutorial will show you several ways to shoot nighttime portraits with a variety of different techniques and for a range of different creative looks.
Coming to you from David Bergman with Adorama TV, this helpful video tutorial will show a few different ways to shoot nighttime portraits. While you might have full control of the lighting in a standard portrait shoot, more time-sensitive events like weddings and events require you to be quick and to often improvise, and that will often mean you will need to learn to produce workable results with a speedlight or some other method. One thing that made my life quite a bit easier in weddings work was using the Westcott Rapid Box series, a line of modifiers made specifically for speedlights and designed to be deployed and used quickly and easily. They are great to toss in your bag for weddings or on-location shoots and can greatly improve your image quality. Check out the video above for the full rundown from Bergman.
