This Instructable will show you how to make concrete boxes using cardboard and duct tape. This example is a planter, but they could also be useful as storage cubbies. This project is nice because it's cheap, quick, and easy.
EASY DIY concrete planter box All you need are a few - pavers, landscape-block adhesive, and a little time. Wait 24 hours for everything to cure and you're ready to move your new planters into place and fill them with dirt and greenery.