But your bike will not turn if you can't get your weight toward the outside of the turn, so force yourself to do so. If turning left, push your handlebar to the left and away from you. The steeper the trail as it goes around the turn, the farther back you will need to keep your weight to prevent the rear tire from sliding. On steep uphill turns you will need to pull your body up hard with your arm toward the outside of the turn. The bike will not turn until your weight is moved to the outside of the trail.
Obstacles pose a special problem.
To get over a root or water bar or rock, approach it from a right angle, compress the front of the bike just before hitting it, and pull up with your arms as you reach it. The front wheel will then hop over it. Next shift your weight forward and let your rear wheel hop over it. If you are riding uphill, you will need to throw your weight more forward as you go over an obstacle. If you are riding downhill, you will need to shift your weight less forward as you go over it.