In transitions, bend Jazzy between both legs with the outside leg back to bring the haunches and the inside leg forward at the girth, dynamic (not holding constantly but rather deep, elastic and available to give a good aid). Carry the inside rein even a bit wide in the warm up to avoid crossing your hand over the neck, and to encourage Jazzy to bend and swing through his body. At this point push the tail out on the circle and have your outside leg back to keep the bend and the outside hind leg active. Keep the horse bending-turning-flexing while doing multiple, prompt transitions walk-trot-walk-trot, keeping Jazzy's inside hind leg active and stepping under, and maintaining a loose but dynamic inside leg with outside leg back to keep the outside hind leg active as well, and heels down, toes up, deep inside leg and strong position in all transitions.
A helpful exercise to school both bending and simple changes: starting in right lead canter, canter down the long side from R to F and make a half 10 meter circle turn down centerline at A, collecting the canter (you can eventually even use this to school large schooling pirouettes); canter a diagonal line toward B, making a transition to walk before you reach the long side while still on the diagonal line. Continue in collected walk to B, then make a transition to collected canter left lead on the long side. Repeat by cantering B to M and make a ten meter half circle turn down centerline from C and canter a diagonal line back to B, collecting the canter as you go; make a transition to collected walk while still on the diagonal line. Making the transition to walk going toward the long side wall helps by using the wall to back the horse off a bit.
Riding the ten meter half circle on the short side between M and C (or between F and A) is your opportunity to really bend the horse well between the outside and inside bending aids. Timing is important: in the upward transition from collected walk into collected canter you must keep the outside rein to maintain collection while first (at the walk) establishing flexion with the inside rein but softening the inside rein to keep the nose up and out in the transition into canter itself. Strong position is important, loose legs, deep heels (toes up), and correct positioning of deep inside leg and outside leg back, while maintaining a deep seat and shoulder blades back and together, and keep the outside rein to keep the collection. In the transition from collected canter to walk, Jazzy must be very supple in the contact and light in the hand so he can land softly into a forward walk; to do this I must have him up and out in a forward carried hand and I must bring the hind legs with me into the transition to walk. Timing is everything. Strong position is everything. Correct contact and connexion is everything.
