perfect wing waggle!
What is a perfect wing waggle? Anything less than 45 degrees is more likely to look like you are wobbling about and can't fly straight.
Generally what feels impressive in the aircraft doesn't look anything like as impressive from the ground.
As has been mentioned, aerobatics competitors start with wing rocks but they must be over 45 degrees in order to be clearly seen from the ground.
Opening and closing the throttle is a much better way to get the attention of someone on the ground.
Normally, if someone is expecting you and you circle overhead then that is enough.
ZA