Get your elbows back connected to your body. This is super, super important because it has everything to do with riding with your seat. Hard to explain, but take my word for it, it's one of the strongest things you can do for your riding. Get your thumbs on top, so that your forearm rotates correctly, HELPing you get your elbow in. Let your upper arm hang down more vertically, and feel that your elbow and your core belong to each other. This is where your true strength lies.
Shorten your stirrup one notch. You are rolling too far forward, into almost a half seat. In fact, at the canter you did a lovely half seat, and if that is what you want, then there can be a time for that, such as with a green horse that is not used to the full weight of the rider, especially at the canter. You do it well, but I think it is more an accidental by product of the fact that you are rolled too much onto your peepee and fishing for the stirrup a tiny bit, thus my suggestion to raise the stirrup one hole.
At times , I see your outside leg rolled outward and pressing the back of the calf against the horse's side. Is it because she is not listening to your leg and is drifting out of the circle? If so, (at some time in the future) address that issue by getting her honestly responsive to a lateral leg.
If you had your elbows out becuase you were trying to open your hands wide, then be sure that you do this without letting the elbow rotate so that it comes up and you are in a "bear hug" sort of position. If you do widen your hands for whatever reason, keep them such you could carry a tray ON TOP of your thumbs, not on the backs of your hands.
Last edited by tinyliny; 10-06-2013 at 08:25 PM.