HELP!!!!!!! Newbie at dioramas!

Okay, I have another post up about this big diorama I am working on. What I could use advice on how to build a scratch built Pill Box for the Ardennes front. It will be a woodland scene wiht alot of snow. I already have the models in mind that will be in them. How can i simulate fake rust from snow and other things. I also want to build little trenches that are about 3/4 under ground. I most likely will custon build it wiht cut down and stainded popsicle sticks. How can i counter sink this? Should i use stirafoam as a base? It will be attached to a homeade table that is 18’’ X 34’'. Also, how do i simulate barbed wire? Any suggestions will be verymuch helpful.

Link to other post- http://www.finescale.com/fsm/community/forum/topic.asp?TOPIC_ID=51387

Try Celluclay.