Just try to take off flying with momentum and confidence forwards aiming your front wheel just over the edge. Then either hold onto the brake if you think you need to, in order to pull the back wheel onto whatever object. If its not needed though, you'll be suprised how much better/easier it is to gap to front without using the front brake. The important part to get right is the leaning back and push the bike forward as you land, if your landing brakeless.