David, I'm not sure that I understand your question, but I will try to answer.
All my hills (Southern mountains

) are constructed using basket weave cardboard, plaster gauze, and plaster of paris. Rocks are both moldings and hand carved.
The trees on Sawmill Ridge are cuttings from a wild bush that grows in the South. Dip in paint bucket of 3:1 water/glue, Sprinkle fine ground foam, hang to dry.
The trees on the other hill are using puffs of Polyesther pillow stuffing.
1. Pull off a glob of poly
2. Roll in your hand for the right size and round shape.
3. Hot glue to mountain.
4. When a small section is complete, Spray paint with cheap black paint.
5. Spray thoroughly with 3:1 or 5:1 water/white glue or equiv.
6. Sprinkle fine ground foam (your choice of color)
7. Use "V" piece of cardboard to blow ground foam into crevices and under the trees.
8. Continue 1-7 until complete coverage
9. Spray again with glue concoction.
How's that? If I didn't answer your question or if you need more specific information on something, please ask again.