I'm not sure if these tips will help you or not, but it may be useful to keep them in mind...
1) make sure you are spotting the direction that you want to end your turn, even if you are doing multiple turns
2) try to keep your center (belly button) pulled in for the duration of the turn, the minute you let your middle loose, you will fall out of your turn
3) arms help! but you need to be sure you are holding them up from your back your sides (right under your arm pits). it will keep your ribcage on top of your hips and help keep you centered. posture is key!!
Hope this helps!!