How can I prevent acne?

I do not have a problem with acne at the moment, but every now and than I will get zits. I am the worst person to get them because I always play with it (not good, I KNOW!). I was wondering what products I could use that work very well in PREVENTING it. I have read about keeping a healthy diet, keeping your hair clean, and such…but I don’t think that will be enough in preventing it!