For stepping stones I'm picturing creating a shape on the ground and then digging the soil out to a depth of 2 inches or so and pouring in the concrete or cement or hypertufa. I picture placing stones within the shape for interest first. My thought is to place sand, push the stones into the sand and then pour. Is this feasible?
No I haven't tried it yet. The plan is to remove them after they set up and turn them over. Then the rocks that are set into the sand will show. Now that I have been reminded of this, and the weather is getting nice, I will do it and let you know.
I wonder if it would be better to push stones or whatever into the top surface of the wet concrete mix... then you would have a stepping stone that "fit" exactly into the shape you dug, with a little sand beneath for stability. Of course, if you're digging shapes like squares or circles, you could flip the finished stone over and it would still fit... but I'm not always that precise.
My nephew is here this week and was intrigued by the idea of doing stepping stones or a hypertufa project, although we have so many potential "camp" activities that I'm not sure we'll get to it.