First, carve the foam to the general shape you want:

Next use your knife to make horizontal slices in the foam. the more the merrier. After a while it will start to pull little pieces out (which is what you want) If the knife starts to "rip" the foam, change blades. It should look something like this:

I used a dark brown paint first on the recessed areas and then a lighter tan color to highlight the surface areas:

Other colors could be used like shades of gray:

You can also add sand, gravel,and greenery for a more finished look:

Finished scene:

Obviously there can be variations to the process....Sculptamold can be used here and there to blend it into the surroundings or cover the strata where ever you wish.
I hope you find this helpful


, SLAP STUPENDOUS JOB
, and GREAT TUTORIAL 


