What you will need: Premixed Concrete (the kind you just add water. You can buy 60 pounds for a couple of dollars) (Mortar mix works even better because it doesn't have the gravel in it, however it is more expensive.) One bag makes about 6 stepping stones. Water, at least two buckets, plastic gloves, garden trowel or something to mix the cement, corrugated cardboard or something to use as a mold like a box, dusk mask or bandana, plastic to cover the wet concrete, pretty stones, ceramic tiles, marbles, or something to decorate the stones with.
What to do:
1. Before you start get everything ready. Decide what shape you want the stones. You can buy molds to pour the cement into that will save you some time or you can construct the molds yourself out of cardboard and hot melt glue. Here is a pattern for the

# six sided stone. Press down hard with a pen when you are drawing the pattern so that the cardboard will fold on the lines easily. Fold up and glue with hot melt glue. You might be able to use the mold more than once. If you don’t want to use a mold, you can dig a hole in the ground, line it with small stones and pour the cement directly into the holes.
# Fill one bucket with water. Use the other one to mix the cement. Make sure you use rubber or plastic gloves when handling the cement it can cause skin irritation. ONLY ADULTS SHOULD MIX THE CEMENT! It tends to spatter when mixing so cover your skin with long sleeves and long pants. Keep the children back when you are mixing. Where a dust mask or bandana when mixing. You don’t want to breath in the dust. Have the children wear gloves when decorating their stones. Keep a bucket of clean water available in case the cement gets on your skin. It’s a good idea to keep some eye wash close just in case or better yet wear goggles. If you are putting foot prints or hand prints into the cement, cover the skin with Vaseline beforehand and have the children wash their skin with soap and water afterwards.
# Follow the direction on the package for mixing the cement. I used about 14 cups of cement to 3 1/2 to 4 cups of water. Start with a cup of water and gradually add the cement stirring as you go. Keep adding cement until it is the consistency of oatmeal.
# Pour the cement into the mold. You want it to be about 2 inches deep. Gently pick up a side of the mold and tap it on the ground to get rid of the air bubbles. Wait until the water on the top is gone, about 10 minutes, or until the cement leaves a lasting impression then start adding your decorations.
# When you are finished cover your stones with plastic so that they don’t dry to fast. This will keep them from cracking. Do not move the stones for at least 12 hours or longer. When they are completely dry, remove the cardboard.
http://www.daniellesplace.com/html/garden_crafts.html