another trick i was taught is to roll your handle hand over, so that the handle is pointing at the water (instead of parallel to it). this rolls your shoulders forward as you land and helps keep your weight going forward.
also, according to the higher learning section in wakeboarding mag, don't pull the handle - just move it. moving it from side to side is what changes your body position. on a 180 there's no need to advance to the handle (since you're not making a behind-the-back handle-pass), and that would just get you off-balance anyways.