A) 3/4" to 2" thick rigid foam, cut and stacked to the rough shape of what you're making.
B) Great Stuff non-expanding spray foam to smooth out the edges and contours.
C) Woodland Scenics plaster sheets dipped in water and laid over the structure (buy a cheap, disposal aluminum baking pan of the correct size for the sheets at your grocery store).
D) When dry, apply earth tone paint(s) and sprinkle various colored and textured turfs while paint is still wet.
E) When dry, spray with cheap hairspray to keep the turf in place.
