How Do I Get Better At Finishing My Layups and Getting More Explosive At The Rim?

Im a very good shooter and I have good handles and very quick off the dribble. alot of times when I play I have my defender beat and I drive to the rim and I'll miss the layup. I have the speed to drive but I dont have the power to finish most of the time. what can I do to get my legs stronger for driving and what drills can I do?