I also paint on stones and rocks, not scenes but animals and some which now look like little baskets of flowers. I go to the river to look for rounded rocks which could later become a beagle or hamster. I have had piles of these rocks in my yard which necessitated a plan to incorporate them into my landscaping until I am ready for my next painting project.
I've placed the rocks around my little pond, and throughout my flower beds. They really add a lot of interest to the areas in which they've been placed, and also help to keep weed growth down a bit. I don't think I'll ever have another flower bed without some rocks placed around the plants. They really help in making the beds special.