Belts
In martial arts, belts signify your mastery of martial skill. I like using this framework for understanding mastery of other skills.
White belt- learn the fundamentals.
Blue belt- learn moves that are 95% effective from each position.
Purple belt- understand the full spectrum, creating your own workspace or sequences with multiply solutions flowing from one problem to another.
Brown belt- avoid boredom, you are already affective in all positions, now try new styles and play.
Black- Judge and acknowledge others progress.