First step is to paint the outside lines of the ornamentation. 
This done, it's time to get to work with hammer and chisel.

Starting as near the stone's edge as possible allows me to adjust the lines should a piece of the edge breakaway. But this granite block is a strong one; the edges stay sound despite the chisel blows. When the lines are chiseled, the next step is to paint in the rest of the ornamentation