I have just started this with my boy and what my trainer said is to give really clear cues or aides in the beginning, to do this you start with moveing your leg either farther back behind the girth for turn on the haunches or move your leg far up almost to the shoulder for moving the front while the back stays in one spot. Also make sure that you are keeping your hips loose so they can swing with your horses movements. For moving the backend to the left move right leg back sqeeze relax sqeeze relax, while doing this keep your left reign with contact so the horse doesn't move forward and with the right reign do a little direct reigning.
For moving the frontend to the left you move your right leg up close to the shoulder keep contact with the right reign while using direct reigning on the left.
These cues are really exaggerated in the beginning so that your horse can start to fully understand, once they have done even the babiest of steps release and praise.
I practice with no stirrups in the beggining because it just seemed easier to give the clearest aids that way.
I hope I made sense and if I am wrong please corrrect me. I hope this made sense. Lol
I am owned by the Sandman