If you want to jump higher, here is a great drill for you. All you need is a medicine ball or overweighted basketball. Hold the ball against your chest as if you were curling with freeweights. Try to touch your knuckles to your chin when holding the ball. Crouch down low like you were doing a leap frog. In a fixed position, begin bouncing at the knees to propel yourself upwards. Bounce with more force each time until you are coming off of the ground as high as you can. After many reps, bring the ball over your head and repeat the reps. Doing this exercise will not only increase your jump, but will provide you with a great warm-up for any game