Taking a portrait at night can be tricky, even with flash. Digital Photography School explains how to make it work.
Here’s the first step:
Set Your Camera
You want to shoot on TV with your shutter speed at 1/10-1/30, and your ISO set to somewhere between 200-400. If you have Canon speed lights on ETTL, your flash will automatically adjust itself for the light necessary to compensate for the lack of exposure as set by your camera.