Are you having difficulty duplicating the fills that you hear in your favorite songs in conjunction with the cymbal crashes within, or following, the fills? Try this. In most instances, the hand that you lead with, or the sticking patterns that you use to play a fill, will dictate which hand is available for cymbal crashes during a fill, or as you come out of a fill. Since you cannot see what your favorite drummer is doing, you must now develop a sticking pattern, and hand leading, that will allow you to successfully duplicate what you hear on a song. It’s all about experimentation. Start slow, and as you "re-construct" the fill, you will begin to see which hand to lead with, and where, as well as what sticking patterns will fit, in order for you to accomplish your goal.