Finishing your eggs doesn’t have the be the end of the carton. Perfect for organizing small items like thumbtacks, safety pins, paper clips, even jewelry, egg cartons’ bottom halves make useful drawer or desk organizers. Green thumbs can use egg cartons as containers in which to start plants: Poke a few holes in the bottom, add some soil and a couple of seeds, and place on a sunny windowsill. And when you’re done with your egg cartons, don’t send them to the landfill — throw them in the compost pile instead.
Credit for this tip goes to The Sierra Club
How to Reuse Egg Cartons