(All attempts at explaining what I learned at the Buck clinic are just that... I might "mis-speak". The best thing is to attend a Buck clinic ;)
I've really been pondering what I learned at the Buck clinic. And I think this year I have really focused on the word "Balance". In my opinion, this is what riding is really all about. And it isn't just about the rider, it is also about the horse. A balanced horse has an engaged hind end. For the hind end to engage, the withers must rise. When this happens with a "soft feel" (without yanking on the horses mouth) then true collection can be pursued.
A review of seat positions:
Position 2 is upright in saddle, above your seatbones. This is the riding position.
Position 1 is slightly forward and used only for upward transitions.
Position 3 is on your pockets. This is used only for downward transitions or the stop.
Backing up is done from position 2 with shoulders ever so slightly back from center of gravity and legs opened a touch.
One exercise Buck had the riders doing was small serpentines. I found a clip from two years ago on You Tube. Bucks demonstration is much better than my summary below!
A series of half circles which are short and tight. He likens it to riding around small sagebrush. The horse transitions from 'bend" to "bend" with, at most, a couple straight steps (if any) in between the circles. This challenges the rider to focus on where the horse's feet are as one must ask for the horse to do a new transition when the feet are in the appropriate place... otherwise the rider trips the horse up! Swinging in this way, doing serpentines, bending laterally, helps release braces in both body and mind.
...and remember, when beginning a turn, ask the foot to move to the side as it is coming off the ground, by opening your inside leg and holding your rein out, from the hip, to "open up". Also, remember to bend the head around with a soft feel, and ask with your seat and legs and your "look" first, reins only if needed.
The following is a pretty good example of a rider doing the serpentine. The clinic I went to, Buck had the riders doing it on the rail. The rider below seems to be doing a bit more of a crazy 8 (perhaps going a bit past that center line Buck refers to in the video above)
Oberon and I have worked quite a bit on serpentines, and I think we are getting pretty good. I even noticed today that their was a bit of "hang time" when he moved his inside leg out about 6" to make the bend. That is great, as I don't want him to hurry - hurrying can create a "down-hill" horse - heavy on the front end.