This is a great drill to do when you are by yourself and want to get the most out of your practice time. The basic idea is this: Every shot you make counts as one point and every shot you miss counts as two points. If you get to ten points on makes before you get to ten points on misses, you win.
To get the most out of this drill, run it at game speed, do not just walk to retrieve your shot; move quickly from spot to spot. Ideally, your accuracy will get to the point where you can make every miss count as five points, and you will still be able to beat yourself. The great shooters can.