Watch for the signs of overplaying in your own playing. This includes:
•Playing anything memorized that you don’t understand: chord forms, progressions, scales, etc.
•Being able to play lots of cover songs, but resorting to a lot of guessing when trying to write your own work.
•Feeling overwhelmed and confused while composing or when placed in unfamiliar musical situations.
The cures to these are to return to the fundamentals of music theory—or the basics of grammar and rhetoric. Sorry, but there really is no substitute for theory in these situations!