My improvised basing process I've set up for SEAF-inspired Imperial Guard paint scheme.

1. Cover the base with milliput or any other modelling clay and roll the texture onto the surface (I'm using Sett Pavement from GSW).
2. Basecoat the texture with Bootstrap Brown .
3. Heavily wash the base with Strong Tone , focusing on the recesses between the stones.
4. Paint every pavement stone with Deep Grey .
5. Drybrush pavement texture with Ash Grey . Be careful not to cover the recesses between the stones.
6. Add light weathering with a sponge to the pavement surface with Brigade Grey and Death Reaper .