Whether you budget your groceries or write out your weekly recipes, it's hard to keep track of what's in your fridge and what should be on your next grocery list. The solution: keep your receipts for a month and stick them to your refrigerator. Every time you eat something, put a check mark by it. This will make things more convenient for you in three ways: you will know what groceries are left, you'll know what items to put on your next grocery list, and you'll also know how much you spent on groceries that month.