Turn a Negative into a Positive
When your horse is using the reactive part of his brain, (jumpy / spooky), do something constructive with the energy.
The natural inclination is to slow things down, or stop the energy. However moving the horses feet will give the horse a leader to follow. Asserting yourself as a good and competent leader requires redirecting the energy instead of simply trying to stop the energy and this reaction will give you a better responsive horse.
Examples of constructive energy redirection include:
rollbacks
circles
serpentines
move the horses feet forward, backward, left and right
Horses typically think of one thing at a time. Whether you want the energy or not, it’s there. By redirecting the horse’s attention to a “job” the horse soon stops thinking about the “scary” threat. This may take 1-2 minutes or it may take 10 minutes, depending on how spooky the horse is.
If you want a good follower, then be a good and competent leader.