Making homemade concrete stepping stones can be a practical DIY project as well as an inexpensive, kid-friendly activity. To give each stone a personalized touch, have your child imprint his hand, add decorations and write in the concrete before it sets. In addition to defining your garden's walkway, you can use these stones to record and chart your child's growth -- simply make a stone each year with an imprint of both his hand and foot. Each one-of-a-kind stone not only provides a permanent record of your child's hand or foot, it also makes a welcome gift for grandparents.
Take a tape measure and measure 2 1/2 inches up from the bottom and on the outside of a 5-gallon plastic bucket. Place a mark with a permanent marker and repeat this several times around the bucket. Connect the marks to draw a line around the bucket. Carefully cut along this line with a utility knife (a jigsaw is easier, if you're comfortable using one) to make a stepping stone mold.
Wear a dust mask and put on rubber gloves for protection. To determine how much quick-setting concrete mix you'll need for the stone, pour all of the dry concrete mix into a large container, then mix it thoroughly to blend the fine powder, sand and gravel. Scoop dry mix into the mold until it is full, maintaining the same proportions of ingredients; you need all three for strong concrete. Transfer the mix from the mold to a large mixing bucket, add water -- small amounts a little at a time -- and mix the water and concrete mix together with a trowel. Continue to add water until the mixture has the consistency of thick cookie dough.
Apply a thin coat of nonstick cooking spray to the inside of the mold before filling it with the mixed concrete. This acts as a release agent, which makes it easier to remove the cured concrete from the mold. Pour half of the concrete into the mold, grasp the sides of the mold and jiggle it a few seconds to help release any air bubbles and settle the concrete. Pour the remaining concrete into the bowl, jiggle again, and smooth the surface with your trowel.
Let the concrete set for 30 to 60 minutes, or until it will hold an impression of your finger or thumb, then begin personalizing the stone with a hand or foot imprint. To imprint your child's hand, have him spread his fingers, rest his hand flat on the concrete and push downward until the concrete is halfway up the sides of his fingers, thumb and palm. Use a similar process to imprint his foot.
Complete the project with decorations, such as flat-sided marbles, mosaic tiles, leaf imprints or shells. Arrange the items and depress them until they are almost flush with the surface of the concrete. If you want to write in the concrete, wait another 20 to 30 minutes. Use a wooden craft stick to write things such as the child's name, age or date.
Place the mold in a dry, shaded area and cover it with plastic. Let it sit undisturbed for 24 hours. Grasp the sides of the mold, flip it over and carefully push on the bottom to pop the stone out of the mold. Before using it as a stepping stone, allow it to cure another seven days.