Open your refrigerator and throw out everything that is outdated. Any foods that you keep around after expiration are only serving to block your view of fresher ingredients (which will also end up going bad). Do the same with your cupboards for the same reason.
Write down the food that you have on a piece of paper. Keep a running list of the food items you have on hand. The list will help you to know what you have when you are planning meals and remind you to use up ingredients before they spoil.
Plan out enough meals for a week on a sheet of paper and write the ingredients that are needed for each meal. This will serve as your master grocery list. Keeping these lists will minimize the amount of time you spend going from aisle to aisle in the grocery store and trying to plan meals there, and it will keep you from impulsively buying items you do not need.
Keep a corkboard, paper and pen in your kitchen. Write down items as you run out of them and add this list to the shopping list before you go to the grocery store. You may wish to keep a separate list for nonfood items, such as paper towels, cleaning products and batteries, and shop for these in bulk to save money. The corkboard can also be a place to tack up coupons; review these before each trip to the store to take the ones you can use and discard any that are expired.
Open up your cupboards and throw out any unusable items. Rusted pans and broken dishes should be thrown out. Keep the good items out on a counter or table until you have all of the cabinets cleared.
Donate any dishes or cookware that you don't use but is still in good condition. Place them in packing boxes, wrapped in newspaper.
Place items back into the cupboards closest to where they are used. Keep pots and pans in cupboards close to the stove and utensils near your preparation area.