Thanks for all the suggestions, everyone! The trainer where my horse is has had me on a couple of his horses - one who is easy to sit to work on fixing position, and one who is a big mover who stops if you screw up your position. :lol: The instant feedback has helped me work on loosening up where I get too tense, and the big mover has worked my abs to help... I still need more work, so will look into options! Funny enough, the big mover is still far easier to sit than my horse, even though she's a bigger mover - because of how she moves through her back and the suspension phase.