The use of the inside leg to the outside hand.
The inside leg dictates the speed and straightness of your horse if used in conjunction with the outside rein, which balances and steadies the horse’s body mass. The rider must always check these aids are correct. Add the outside leg to help with the balance and you are left with the inside hand which is soft and maintains flexion and waits for the horse to stretch and seek the contact.
Contact is about a stretching through the whole body, starting at the back of the horse, over the back into the mouth, which you as a rider should feel in your fingers and palm of your hand. Riding with a balance strap attached between the D rings on the front of your saddle, allows you to hold it with your rein and this ensures a quiet and steady hand.

On a circle, working in working trot. Stretch the horse’s neck and head forward, lengthening and slightly lowering the frame without losing the “feel”, or changing the weight on the rein. Then gather the rein again without disturbing the tempo. This can also be ridden in canter if the canter is correctly balanced.

I came across some photos of many years ago, and thought them interesting because they demonstrate how styles and education has changed. Joke Hall was riding the Lipizzaner, and Christilot Hanson (Boylen) was 17 years old.

Dressage styles