Rockstar (“Rocky”) and Wesley are two of the horses in my winter maintenance program. Rockstar is an Applaoosa and Wesley is a Clydesdale/Thoroughbred/Arabian cross. Both are tall, lean, hard keepers, and both tend to be reactive, although in different ways.
In Parelli terms, Rocky is innately a right-brain introvert. He has to think before he moves his feet, and when spooked, he will freeze first and then possibly explode.
Wesley is a right-brain extrovert who has to move his feet before he can think. His reaction to a fearsome thing can be quite spectacular.
Before a session, Rocky will amble across the arena, roll, then come back and look over the fence at things going on around the ranch. Wesley gallops around, head and tail high, almost floating with exuberance.
This is not the only thing we do in the session, of course! But it is an excellent skill for every horse to know — and for every human to practice as well, as it doesn’t help to teach the horse to relax if his human is wound tight and jumpy.