the first step is to learn the inverted harrier, i see a lot of pilots fooling around with rolling fly by's but the harrier is more attitude than flying. when your confident with the inverted rudder inputs practice rolling from up right to inverted high a attitude and back again. while in the knife edge portion of the roll watch the pitch of the plane while the rudder is deflected. too much rudder will cause you to over control, you will always be fighting the elevator to correct what the rudder input has caused. dont practice only left or right rolls, do it both directions as this will make you a better pilot. rudder rudder rudder gotta have rudder. RR