I can't see a whole lot, but what I could pick out, you should sit back a lot more. You are sitting very forward. Try to roll your hips back under you, that made my transition from hunt to dressage better. Also, on your down transition from trot to walk, it looked like you were waiting for him to walk before you stopped posting. My one instructor ALWAYS got on me for that. Sit and then ask for the walk. It will make the transition feel a lot smoother and more natural. :) He seems to have a very rhythmic and even trot, which is great! I agree with tinyliny, try to get his free walk as forward as you can. Judges tend to focus on that a lot! Great job so far though!