Ever wonder what to do with a metal cookie sheet when it’s time to replace it? If it’s aluminum, the easiest way to dispose of it is to simply toss it in your curbside recycling bin. Just like aluminum soda cans, the cookie sheet will be melted down and made into new aluminum products. If you feel like doing something crafty, try this upcycling idea: Paint a few layers of chalkboard paint on the sheet, and turn it into a message board. It’s quick, quirky and fun way to keep messages and to-do lists handy in the kitchen.