When buying a dozen eggs, look for paper pulp or cardboard cartons. The majority of egg cartons are already made from recycled materials, and they are also 100 percent biodegradable. Tear up the paper cartons and add them to your compost bin or even work them into your garden as mulch. Just break them into small pieces and use a small hand shovel or trowel to place them around plants. They'll break down quickly and help with drainage in the soil.