Like LJ says, practice A TON of 180 to stomach bounces with lower bounces. Then once you've got that motion in your brain, set a high bounce and do that, then push your feet back under you. You'll probably do a bunch of cork 5's when your learning them. If your doing more of a lincoln, then make sure that your really thinking about spinning both your shoulders and not letting them flip.
Kick the imaginary wall at 90 degrees, look straight down at 180, and if you do it right the last 180 will come around.