Clear your chosen checkerboard area of all grass and weeds and then rake it over, making the area as flat and even as possible. At the same time, remove any stones you come across.
Use a wood board — such as a scaffolding plank — to compact the soil, making it more even and easier to lay the pavers on to. Move it gradually across the area, walking across it each time it is laid.
Measure the pavers and then, on opposite sides of the area, mark out the measurements with sticks and stretch twine or string between them. Repeat on the other edges, making sure the lines are parallel and perpendicular.
The squares on which the pavers are going to be laid should be covered with sand to a depth of about two inches. This will give the pavers something to bed into, and will make laying and levelling much easier.
After you have put all of the sand in place it will need to be leveled out and consolidated. This is most easily done by “firming” it down lightly, all over the square, using the back of a rake.
Mix up a wet mortar of four parts sand (half and half sharp sand and building sand) to one part cement or use a ready mix. Place a trowel-full in each corner and one in the center. This will firmly hold the paver in place.
Put the paver carefully in its place and use the wooden end of a mallet gently to knock the corners until it is level. It is essential to use a small spirit level here, checking the level in all directions.
To bring the planted squares up to the level of the paved squares, fill in with topsoil. This will help with maintenance in the long run, particularly if you are sowing grass and will need to run a mower over the pavers.
Plant your squares. We used creeping thyme, but other good choices would be Soleirolia soleirolii, chamomile “Treneague”, or grass. Grass could be sown from seed in the fall or spring or cut pieces of turf to fit.
Keep your new plants well watered for the first season, until they are well established. Weed regularly until the plants knit together. New grass seed will need several months before it can be walked on.
Children are bound to create their own stories of stepping stones over swamps and fast-flowing rivers but they can also use colored (and temporary) chalk to make a game of hopscotch — and enjoy the scent when they miss a step.