If you want to make your own stepping stones for the garden, store-bought molds give you a quick way to get started -- but the style and size options are quite limited. Instead, make your own molds from sand, plastic containers or just about any shallow, flat tray or household object durable enough to hold the cement until it dries.
Sturdy, thick cardboard boxes morph into stepping stone molds with only slight modification. Cement mixtures harden into the interior shape of whatever they're poured into, so the inside bottom portion of the box must be flat and smooth. Cut a sheet of card stock or cardboard that fits the bottom snugly to make a smooth surface. Cover the inside walls of the box with plastic wrap and petroleum jelly so you can remove the hardened concrete easily. When the stepping stone becomes hard a few days after you pour the cement, remove it by flipping the box or by tearing the box apart, if necessary. Smooth away any imperfections on the stepping stone by rubbing your hand over it while wearing a work glove. The texture of the glove is enough to abrade away the flaws.
Sand presents potentially infinite options for stepping stone designs, because it can be shaped in so many ways. Fill a plastic tub several inches deep with clean play sand, and then wet the sand slightly. Press a flat-bottomed object into the sand -- such as a casserole dish, cookie tin or even an existing stepping stone -- pushing it down at least an inch and compacting the sand in the process. Lift the object away, and pour the wet cement mix into the sand impression. If the sand is damp enough, it should even pick up details, if any, left behind from the object's impression, such as shells or seahorses.
You can use cake pans, pie tins, shallow trays and disposable baking pans to create stepping stones. These forms are durable and may be reused, as long as the inside is covered with petroleum jelly -- or plastic wrap and petroleum jelly, if you don't want the pan to get greasy. Plastic tubs and cookie tins may be used in the same manner.
Wooden Reusable Molds
Create your own square or rectangular wooden molds by making a thick frame shape out of layers of plywood -- this frame must be at least 2 inches thick to make a sturdy stepping stone. Create a wooden base that fits under the frame, with a built-in platform in the center that holds the frame in place and allows four side boards, taller than the frame, to be added and removed each time you create a stepping stone. Line the form with plastic, and then pour the cement. Once the cement is hard, remove the side boards one by one and lift the stepping stone out.
Stepping Stone Success
To add strength to your stepping stone, pour 1/2 inch of cement into the mold, and then add a piece of hardware cloth as large as possible without touching any of the mold's edges. Pour another 1/2 inch or so of cement over the hardware cloth. To add embellishments such as beach glass or shells to your stepping stone, cut a piece of contact paper to fit inside the bottom of the mold, and then set the paper into the bottom sticky side up. Adhere your add-ins face-down on the contact paper. This bottom layer becomes the top of your stone once the cement hardens and you peel the contact paper away.