If you have a cargo unit strapped to the roof of your car, get rid of it. While it may be useful for carrying camping gear for a road trip, it wastes gas when you're not actually using it. Cars are designed to be as aerodynamic as possible, and a cargo unit on the roof decreases your car's efficiency by as much as 25 percent. If you must have a cargo box, consider a rear-mounted one; it decreases your car's efficiency only 5 percent.

Have some old keys in your junk drawer? Did you know you can use them to help the homeless? The Giving Keys, a nonprofit based in Los Angeles, works with homeless people and trains them to make jewelry out of old keys. The keys are upcycled into rings, pendants, bracelets and more. The workers earn an income, and it helps them get off the streets and back on their feet. To learn how to donate your keys, or to shop the collection, visit thegivingkeys.com.

Did you know that baking soda can expire? One way to test it is to simply spoon a little bit into a glass filled with white vinegar. If it fizzes, it's still active. If not, it's dead. But there's no need to toss it into the trash. There are lots of uses for baking soda around the house. You can use it as an all-natural abrasive on tough-to-clean areas like a stovetop. But one tip that's key for pet owners? Use it to neutralize accidents. If your dog or cat accidentally relieves itself on your hardwood floor, wipe up the urine, then sprinkle baking soda on top. It will absorb it and neutralize the acidity to prevent damage to your floors.