make this shelf in 30 mins or less
I needed a shelf for my son's toys, and I happened to have a couple of fruit crates in the basement along with some furniture wheels. A few minutes later, they had turned into a perfect shelf for my kid's room.
Take the fruit crate you want to be the bottom shelf and attach the wheels to it using the screws and screwdriver - one wheel per corner.
Put the other crate on top of the wheeled one and nail them together.