Go to your back yard, Dig a hole, Jump into it, Jump out of it. Dig it deeper, Jump out again. Dig till you can't jump out. Keep trying every day till you can jump out. Dig the hole even deeper. If you can't dig anymore the strap weights to your feet. Before you know it you'll have a seven foot hole in your back yard that needs filling. Hell, all that digging would be a good arm and back work out. If you're a real bada$$ dig the hole with your hands.
By the way I'm not kidding at all. If you want to jump high really this will do the trick. If you're really serious and you can spare 4 square feet of grass then what's stopping you? Because it's rediculous Hell, I think doing Tai-Chi in the front yard at 5 in the morning is rediculous but that didn't stop my mom.