Use binoculars so you can tell where the scoring rings are (probably at least an 8X is needed). The biggest problem is that there is nothing to aim at, as you said, but that is what makes it good practice for hunting. If you are primarily a hunter, I would always shoot where you would on a real animal, regardless of score, because the kill zones on 3-D targets aren't always realistic. If you want to be good at 3-D, you must learn the targets' kill zones.