As I did: I marked the path, removed the sod (3-5 cm.), Put the formwork (I used old plastic panels), filled up the sand cushion (3-5 cm), filled it with a solution of 1: 2 (be sure to mix dry, and then only pour water). When frozen, I cut the surface in the shape of a stone, rounded the corners. I floated with cement through a colander and smoothed the seams of the cut stone. After about 12 hours, either watered abundantly for two days, or it is possible to cover it with a film. Formwork can be removed 4 days after pouring.