(I always seem to come out of stall turns upside down)
Slightly off topic, but me too, until I learned the proper lookout technique for a stall turn. You then instinctively correct the pitch and exit with a 90 degree downline.
The trick is to look over your (left) wing on the way up to see if you obtained 90 degrees and once you yaw the aircraft (left again) at the top of the stall turn, follow that point on the horizon with your gaze, and instinctively correct, until the nose is pointing to that same point. Then follow the nose down, keeping the stick position the same, or slightly pitch back.