Flash to freeze motion with a slow shutter speed

Using a slow shutter speed combined with your flash can create more depth and interest in your background

There should be as little light on your subject as possible. this will make your focus better. Fix your focus on your subject, by pressing half way down on your shutter. make sure that you have some ambient light in your background. Your shutter speed ,if you can control it, should be slow. The speed that you choose will be  dependent on how bright the light is in your background. If you move your camera during the exposure. You can create some interesting streaks and light patterns.

 If the is a subject that is moving through your frame lock your focus on the subject and follow the subject through the frame. This is called Panning your subject should be in focus and your background should be blurred.