Mistake No. 1: Cleaning a Cold Oven
We're not saying you should start scrubbing when it's hot, but a warm oven is easier to clean than a cold one, according to Great Green's LeBow. Turn it on low (e.g., 250°) for 10 to 15 minutes. Then turn it off, spray a nonabrasive cleaner (or spread a homemade baking-soda-and-water paste) all over the inside, and let it sit for 20 minutes. Scrub with a nylon brush or pad and use a sponge to rinse it off.