If you would like to jump higher for sports or just for pure athleticism these plyometric exercises will challenge your muscles to optimize their ability to perform. This will involve a series of jumping exercises with weights and props.
Deep Knee Bends --- Be standing. Slowly bend at the knees while keeping your back straight. Slowly crouch down as low as possible (it shouldn't hurt) and slowly rise back up. Do this 15 times. Over time increase to 20, 30, etc.
Deep Knee Bend Jumps --- Be standing. Crouch down as described above but fairly quickly, almost touching your bottom to the ground, then explode upwards as high as you can. The moment you land, immediately crouch and launch back up again. Do this 15 times, and when you can, increase to 20, 30, etc.
Toe Raises --- Stand regularly, then raise up onto the tips of your toes. Lower back down. Don't just rock up and down, do it slowly (not too slowly) but steadily. Repeat 30-50 times.
Toe-Raise with Weights --- If you have any sort of weights, holding/wearing them while doing these toe raises will help. Use small weights (a mere 5 or 10 pounds is fine) and work your way up.
Stomach Crunches --- We believe that sit-ups are bad for your back. Stomach crunches, where while lying on your back, using your abdominal; muscles and keeping your back straight, you rise up just enough to lift your shoulders off the ground, are better. Do them often - perhaps for 10 minutes in the morning and 10 minutes at night.
Jumping Rope--- Jumping rope definitely helps your vertical leap. Jump rope while watching TV or something. Make it a habit.