I briefly mentioned this technique in another post, but I wanted to throw up a picture for visual-learner types (like me!). This is a great way not to waste money on those silly little plastic plant labels that you buy at nurseries:
Take a 1 quart plastic yogurt container and make vertical cuts about 3/4″ apart all the way to the bottom. [pictured below]
Then make a cut all around the base of the container, snipping off each tab. You can cut them to whatever size is appropriate for the pot they’re going into, and they’re easy to write on with a permanent marker, or better yet a grease pen or crayon (more UV and rain resistant).