Triple pirouette killing me?

I can only pull a double pirouette, and though I have wonderful jumps and flexibility, turns are my greatest feat. I know that when I turn all my weight goes to the outer side of my foot, and I know I need to adjust my weight more evenly over the whole foot (and perhaps put more weight on the ball), but how can I accomplish this? I consciously know my mistake, but my body never corrects when I'm trying to turn