Get down on the ground and vault forward with the method I posted earlier. In the air you want to either stretch out (contract pecs, raise shoulders, extend hips) for a diving sort of thing, which works pretty good but is a little unpredictable when it comes to knowing how far you'll fly; you could also do a tucking jump, where once you're in the air, you contract hips and knees and lower shoulders (extending pecs optionally). I've found that method to be better for a more balanced but overall shorter jump.