I used poly fiber on my mountain by spraying the mountain with adhesive first, stretching the poly fiber on to it, spraying again, then dusting on woodland scenics blended grass. It's ok, but not "awesome". I see some guys making millions of polyfiber balls dipped in glue then folliage, and painstakingly placed on the hills. Which do you prefer? I have nick named myself "the impatient modeler", cause I don't have patience to make a million trees.