Nikon D3100 - Good things to know?

I'm doing my first set of senior pictures soon, and I feel like I know my camera pretty well, but I'd like to know it better. Are there good things to know? Focusing info? Setting info?

Use a tripod.
Make sure that your subjects are a few feet from the background
Use standard portrait lighting for the first few shots. Get creative if you like later in the shoot.
Make sure that the persons makeup is done correctly so you don't later have to spend your own time correcting skin flaws.

Use either your 50 mm f/1.4/f/1.8 lens or your 18-55 mm lens at 55 mm.

Knowing your camera pretty well isn't enough. You have to know photography very well too to know what questions to ask exactly.