Select stone tiles that are suitable for outdoor use. It’s best if they’re not finished, a smooth finish can be slippery when wet, A natural slate or flagstone sized 12” x 12” works well.
Submerging each stone tile allows for a flush hopscotch surface and allows you to develop a solid and level base for each tile. A solid underlayment will also prevent the stone from cracking. Use a landscaping edger or the flat edge of a spade shovel to edge along the perimeter of each stone. Use the shovel to dig out two inches beneath each tile. Having cut in around all edges makes it easy for the shovel to lift a very precise area without disturbing the ground that you want to remain intact.
Shovel sand into each hole, leveling it with the shovel. Use a tamper to compress the sand to a firm, packed layer just 1/4” beneath the soil surface. If you do not have a tamper (or perhaps your tamper surface area is larger than your tiles) use a small heavy object like a brick to compact the sand and create a level surface.
Dust a thin coating of sand along the compacted sand surface. The soft and uncompressed layer will mold into the crevices on the underside of the natural stone, helping to make it more stable.
Position each stone in place and use your own body weight to stamp them into the underlying sand. If you sense any wobbling, lift the stone and toss more soft sand into the space. Re-lay the tile and check to see if the surface is more solid.
Adjust the soil around the edges of each tile to make sure the surface is as flush as possible. If you are working in an area that is already lush with grass, you may be done! If your selected space is still soil-covered, layer the surrounding area and the soil between each tile with grass seed to help it fill in and become lush.