Shoot Wide Open

By shooting wide open, I mean shoot as close to your wide open aperture as possible (so if you have an f/2.8 lens, shoot at f/2.8 or one stop up). This will pay off in two ways:

1.	This will blur the background, creating a more dramatic, dynamic, and uncluttered photo of your subject. Busy backgrounds are a problem when shooting sports, and shooting with a telephoto lens at such a wide open aperture gives you a very shallow depth of field (meaning your subject in the foreground is in focus, while the background is out of focus).
2.	You'll be able to shoot at faster shutter speeds, which will greatly help when shooting indoors under artificial low-light situations.