Babe Ruth was asked what he thought about when he was at the plate. His reply was that if he had to think about it, he never would hit the ball.
The conscious mind has to occupied with a single thought so that the subconscious mind can operate with no hesitation.
Some research has shown that it may not matter what you are thinking about, as long as it's just one thing. I don't think that I agree with that, I think that the one thing has to be the spot that you want to hit, which is pretty much what everyone else has posted.
IMHO target and hunting are a little different. In target, I find it best to focus, center and think about form up to the point where I reach anchor. Then it's got to be total focus on the spot. For hunting, I don't usually have time to do all that, it's just find a spot and focus on it. If your subconscious doesn't know what to do then, you need to practice more.
Just my opinion,
Allen