Hi, I'm sort of in your shoes, just started doing dressage about a year ago, and had been riding hunter/jumpers for about 17 years before. My big thing I've had to work on is my seat and hands. The position of your seat changes a little, which will easier for your to get with a dressage saddle. My hands have also been a challenge, I'm used to riding with my hands lower, and closer to me, but to get my horse stretching downward into the bit, I've had to put them higher and more forward to allow stretching. It is a big adjustment, but is so worth it!! I've enjoyed learning how to do dressage and develop a great connection with my horse, in fact we are going to our first show next month, doing training level 1 & 2. Good luck!!