Approach an obstacle about waist height and place both hands flat on top. You may add a small hop before, if it helps. After placing both hands flat on top of your waist high obstacle. Hop up as high as you can and tuck your Knees to about Chest High and bring yourself over. The main problem with this Vault is people having a fear of cliping their toes and falling face first. Practice on lower obstacles about thigh high. Once you feel comfortable enough to move up it should come easy and natural to you.