RE: Straight
You're going to have to sacrifice one of them if you really want to "practice" with them.
If you've got an open field you can shoot in, set a cucumber on a stick and walk back 20 - 30 yards and shoot it. You may break the blades, you may not. I did, now I'm down to two.
They fly just like your field points. You don't need to tune your bow to them.