I'm sure this old hat for the more experienced riders.
I've been having problems with Willow tossing her head when we are working in the arena. When she does this, I tense up because she isn't listening, and pull too much on her mouth which intensifies the head tossing.
Anyway a friend suggested riding her in her halter to get us both to lighten up. I also saw a thread on here where another member suggested the same thing for a similar problem.
It worked wonders. No heading tossing, just a little over arching of her neck a couple times.
I was forced to use my seat and legs a lot more. I didn't realize how much I was depending on my hands in the turns and pivots. I even got her to do a slow spin.
Not throwing my bit out just yet, but thought I'ld share.