Masseter muscle botox gets surprisingly little attention for this and derivative issues. Not too expensive. Very simple walk-in procedure, don't need consults. Zero effort. Not permanent (both a con and a pro), but some say their problem doesn't come back even after it wears off.

Pretty much all other interventions (besides self-awareness/lifestyle) are way more involved and don't have a great record either way. Nothing is proven about botox either, but seems like the best thing to try first.