...I recommend -two- targets when training.
First, a very small target. This is the target you're actually aiming at.
And second, a paper target behind that one.
In truth, the second isn't a target at all, it's a training tool. You aim at the small target because smaller targets instill better training ("Aim small, miss small"), and because it's much more satisfying when you do hit it.
You put the paper target up so you can identify what is being done wrong when the primary target isn't hit.