What kind of equestrian activity can you do when it's too cold and too dark outside to ride?

After my terrible mounts at equestrian vaulting practice the other day, my vaulting instructor told me my homework is 50 jumps over the vaulting barrel every night.

The problem with my mount right now is that 1) I can't seem to get off of the ground right now; and 2) I'm turning into the horse, which is completely incorrect form, and if you're not careful you'll find yourself underneath the horse.