I save all boxes and then cut them down the sides to make them flat. I use them as a base for my garden paths, especially in the veggie gardens and cover the cardboard with weed barrier. If I don't get to laying down the weed barrier right away the cardboard at least temporarily keeps the weeds down even if it isn't elegant. In one garden I cover the cardboard with a thin layer of straw so it looks better. I don't care which side is up since it will eventually be covered anyway!
