I agree with Romy - you can do almost everything in saddle that you can do from the ground. Just be prepared for abrupt stops when your horse hears the marker signal
The best thing to get your horse's focus is surely practising micro-communication. If you want to focus on calming down, you can reward specifically for any calming reaction. Release of the poll when you ask for a bend, or dropping the head. I have a voice signal for lowering the head which is helpful to put the horse in a calm state by itself.
I also love to ask for any exercise we are currently working on (except rearing
). It is usually the most highly reinforced exercise at the moment, so chances are good that it brings the focus back to me in a positive way.