Three tools of training!
The first, that looks vaguely like a fraternity paddle, re-enforces on edge mechanics. When used to throw a shot it glides easily through the air so long as the thin edge moves toward the target. When the mechanics are wrong the flat edge drags in the air, much like an airplane wing, causing the sword to move incorrectly.
The second is an old sword stripped of its hilt, and used for pel work. Pel work is important for learning muscle memory, throwing combos w/ flow, and learning recovery. It's important to know how your sword rebounds so you don't hit yourself in the head. When throwing combos move about and establish flow. Your opponent doesn't stand still when your fighting so why should you practice your shots in a stationary position.
The third is a light piece of bamboo with triggers. This little whippy thing I use to practice new shots with and do slow work with a partner. Since it's so light I can tap my practice buddy without fear of serious injury, and don't need to worry about hurting myself by throwing a shot incorrectly.