Check out Janet's Head-Flipping post today! It's my light bulb moment of the week, without being able to ride a lesson.
A few months back, Ransom was tossing his head in rides - He'd decide "enough" bit contact, and start yanking the reins from my fingers. I figured it was just too much bit contact, and let out.
In my BRM lesson, Barbara scolded me for this. "No! He's taking advantage of you! Yank on him, and growl "no". He'll quit it eventually when he realizes that isn't the release he wants."
So I did. And, thinking about it, he hasn't been throwing his head around in forward trot & canter. In the transitions from collected walk to extended walk, he still tries it occasionally, but not nearly as much as he used to.
It works! Light bulb!