mssg2laura
White Belt
Try lifting your left foot slightly and then using it as a springboard (pressing it hard into the floor) to launch your jump. For some reason when I tried this it not only improved the height of my jump but my ability to land lower to the floor. If jumping in general is an issue I would suggest jumping onto a step/platform about 1 foot off the ground (a set of 15 slow jumps focusing on a light landing, and a set of 15 fast jumps with no pause in between). Jumping rope will also help with coordinating your jumps. Keep practicing - you will succeed!