Nice wheelie biotch!!!
I don't understand why people have trouble doing wheelies? Putting your foot on the grab bar isn't a real wheelie....but I guess it's good to learn how to balance.
I recommend getting comfortable just doing rolling wheelies, like popping the tires up and seeing how long you can keep them up with the throttle.
Once you're comfortable getting the front wheels off the ground a bit, like in the above pic, tap the front brakes when the wheels are in the air...it will keep you balanced better. By now you'll know that you want to be sitting back on the seat, pulling up on the bars at first, and then once you're in the air you lean forward a little bit...depending on how much you weight, how tall you are, etc, to get it to balance. If you flip over the back, you were on the throttle too much and went past the balance point. Once you find that balance, you'll feel it, you can let of the throttle a lot and the front end stays exactly where it is! Practice in a big flat field, prefereably with soft grass!! But then keep in mind, if you master wheelies in a field, you'll need less throttle to get the front end up if you were to wheelie on pavement.