For me it is teaching kids to pick up subtle body movements and timing patterns of pitchers. My motto has always been that if you have to wait for the pitcher to move his non-pivot foot, you're already too late. I rarely see a pitcher that doesn't have some tell that you can read and get a jump on him a split second before he's about to start his delivery. As an example, we faced a pitcher yesterday who clinches his butt cheek just before he goes into his delivery. You could actually watch for the ripple in his pants as a sign to take off on the steal.