I would so recommend the book The Rider's Guide to Real Collection by Lynn Palm to anyone. This book has exercises on how to train a horse transitions between gaits and how to lengthen strides, turning on the forhand and haunches from the ground and saddle, sidepassing and flying lead changes and much, much more! This book is very well illustrated and I know that helps me..I learn better by visuals than anything else so if I see it or can feel it I will pick it up a lot faster than any other way. Anyway this is a very awesome book! :) If you get it and read it I would love to hear your opinion as well!