Paper tune, brother! I just built my first set of Red Osier Dogwood arrows, and shot them through paper today without fletching. I feel like I learned volumes about spine, arrow weight, and what side of the arrow needs to face the bow. It's incredible how much of a difference putting the arrow a few fractions of an inch further or closer to center (in my case, by switching between my new bow and old bow, one of which is nearly a center shot) will affect the spine you need to shoot.