This isnt pretty, but you can see my "style" of making the pieces. I did take some short cuts, but you will get the point.
Start with standard block of foam:
I rub a screwdriver at a 45 degree angle froming stratta lines
I dig into an area to make a deep recess.
I rub the shaft across the edge to roll the top
I chip a portion of the edge to create a harderedge
I rub my finger to soften certain points, and I also puch into the recess to crack the top area off
piece ready for paint
The piece painted and flocked
So thats about it for the way I do it. I am working on a much more detailed tuturial for an entire board as we speak. you can really see how nice the stone work comes on that piece.
Let me know if this is usefull or not. I didnt do minor stratta and some other tricks on this one as it is a throw away piece, but I think you get the idea.