December: When in doubt, throw it out
Make room for storing holiday feasts (and leftovers) with a deep cleaning of your refrigerator and freezer. Before cleaning a fridge or freezer, you'll first need to do a little prep -- where will you store frozen items so they won't spoil as you clean? Keep coolers on hand to temporarily store foods (although keep in mind you can generally leave most refrigerated (perishable) foods at room temperature safely for under two hours).
With the appliance empty and the temperature setting turned to the off position, remove any shelving, crispers and ice bins or trays, and clean them with warm soapy water. Same with the doors and walls -- give them a good scrub with warm soapy water.
Don't forget to clean underneath the fridge or freezer, too. Use your vacuum's brush attachment to clean away any dust or debris that has settled under the appliance as well as on its coils and vents.
To learn more about cleaning and organizing, check out the links below.
Living in clutter can actually be very bad for your health, both physical and mental. HowStuffWorks digs into the mess.