Just a suggestion as you move it up a notch, go get some altitude to match. Plan each maneuver out, one at a time. You tend to lose it more frequently when you roll right from one to the other. I just practice flying into and out of the box for each maneuver that I try. Sometimes, I will deliberately only do one or two different maneuvers in a flight, just to work the execution of them. I have spent years at it and haven't gotten as good as I want, but so far, I can recover from any of them..