Looking for some advice from the more advanced martial artists in this group. In my jujitsu class, we spend about 80% of our time training in grappling techniques, and about 20% on striking. I've somewhat improved my striking skills by training on my own with a punching bag in my apartment. My problem is that-while my striking technique has improved-my reaction time is still terribly slow. When I'm sparring, if I can get a hold of my opponent and take him/her to the ground, I usually win, or at least give the higher ranks a serious challenge. But before that happens, my opponent usually sneaks in several punches and kicks that, if they had made contact, would have knocked me out cold. My strikes, on the other hand, are sluggish, and my blocks are almost always too late. So, my question is, what drills can I practice on my own time to improve my speed and reaction time?