Back in my earlier life, I shot air pistol and .22LR on a German pistol team. Man, if your trigger press and follow-through weren't perfect, that slow moving pellet went chasing wild geese. After the air pistol, it was no trick at all to stack the .22s in the 10 ring (9 ring at the worst).
I just picked up a LIGHT longbow - a 33# @ 29" Mohawk. Same thing. I grab a quiver full of arrows and proceed to spread them all over the place if there is ANYTHING wrong with my form. When I start grouping the arrows nicely out of the pretty little toy, I grab my hunting bow and the arrows just want to stack themselves on top of each other. Just like the air pistol, it's the greatest training tool I've found yet.