I prefer a light seat, so the horse can use its back freely, i say this often, whenever people talk about sitting deeper into their horse, i think perhaps its because i am a heavier rider, and because i had a male rider that i worked for, who was heavy as i am now, who used to use a lot of back and seat and i always had to take care of his horses sore backs. I prefer not to use shoulder imagery, because i have seen people use burlesque like shoulders and not bring their aids to their core or seat. If rider are told to adjust their shoulders often they do not carry the adjustment from their center and it results in a hollow rider back, instead of the more ideal flat back. that said i find myself sometimes sitting more forward that others consider ideal. something i have seen in several riders i admire so it does not bother me too much any more. okay having said that, piedmontfields, i know your advice works really well for many.
Flight, i see your hand moving downward in your half halt on the outside rein, slightly, which i think can be counter productive.
It is funny because, Flight, my latest video is very similar to yours and i found myself comparing the two side by side, ( I envy your lightness of seat and power of your lovely horse). I agree that taking the time to better prepare for your transitions effectively will help you. effectively is my key word, you want to get the horse to give you the correct response to your preparation, if they do not, then add a step, to improve response, before continuing with the transition.
It is easy to give the preparation, and then proceed with the transition, without being sure that your horse has given the correct response to the preparation. Kimba tends to anticipate the upward transition, get a bit short strided and tense, instead of re-balancing and waiting. I will some times put in a small circle, a few steps of shoulder in, or something to modify and specify the response i would like, before going to the transition. just because you prepared, does not mean you have to go ahead with the transition, if the response was not the correct one.
( reminder to myself as much as to you

)
i do enjoy our training goals threads. thank you to everyone who participates!!