Positioning yourself on your bike

Get used to getting into the basic "attack" riding position. Butt out of the saddle, eyes forward, feet level, arms relaxed. Use this position any time you approach anything technical or a descent. Don't be crouched, stand up tall, but don't lock your joints.
Think of your body as a spring. Let your arms and legs work with the suspension.
If you just "sit" on your saddle and let the bike take the hits for you, a number of things happen.

First, your ride is going to be rougher than if you get out of the saddle. Second, this will limit your skill growth for learning how to maneuver through technical terrain. Some folks think that having a FS bike excuses them from having to get out of the saddle, or use their body, but they are wrong. No matter what kind of suspension you have, you should focus on being dynamic, active, "one with the bike" instead of passive, or just sitting on the bike while pedaling.You should be able to move up and down, forwards and backwards, and side to side while riding your bike, especially out of the saddle.

Tomac said it best: "the saddle is not a butt rest!"