I've heard stories of people taping up motivational pictures and sayings to their fridge and cabinets xD You know, your favorite models or "just say no!" type things.
What I usually do, is everytime I get a craving for something sweet, is I gorge on something healthy til I'm full. If I want a brownie, I'll eat four or five huge carrots first. If I still REALLY want a brownie after that, I might have a bite, but I'll be much fuller and less inclined to eat ^^