Place a container on a work surface that will be used as a mold form. Choose a cake pan or other similar container.
Position a mixing bucket or container nearby and pour quick-set concrete into the bucket. Add water based on the manufacturer's directions. As a rule of thumb, add water gradually and mix with a stir stick until you achieve a thick mixture.
Scoop the concrete into the mold form and tap on the work surface to settle. Evenly disperse the material and remove air bubbles.
Assist children as they press their hands into the quick-set concrete. Position the hands in various positions including fingers spread apart. Wipe hands clean with a damp rag and then wash with soap and water thoroughly.
Add decorations including shells, stones and tiles. Choose items based on a theme as an attractive detail.
Place the molds in a warm and dry location for at least three days before attempting to separate the stepping stone from the mold.
Spray the stepping stone with an acrylic sealer to prevent damage from water. Allow the stone to dry and apply a second and third coat if desired.