I do not do very much to keep from snacking at night. In fact I often have a snack at night. Since I know I like to snack I often avoid eating desert at supper and have it as my snack. I eat when I am hungry. To reduce the cravings I do relaxation exercises and try to avoid being bored. Stress and boredom can lead to food cravings when you are not really hungry.
Snacking is not always bad. Sometimes it can even help you lose weight. You just need to make sure your body needs the food.