make sure you are using a hard enough gear. If I'm going to stand on a climb, I usually go up a few clicks in the back before I stand. If I'm going to spin, I go down a number of clicks. Also, I tend to pull back on the handle bars when I'm standing and make sure to look ahead at where you are going. It took me a while to learn how to stand, but it is definately worth it when you figure it out. Good luck!