If you have a fridge, put everything that is edible in sealed Tupperware. Screw plastic bags. If you live in a college dorm your main concern is that mice don’t get into your food. Tupperware seals the smell of the food in. Keep your cereal in Tupperware as well. It’s also a lot easier to see everything in your fridge when it is in plastic boxes, instead of everything being thrown on top of each other.