George
Lots of previous posts for ideas for you to think about.
I have beat, grind, cut, whacked and numerous other ways worked with foam. I also used my table saw and chop saw.
I copied another forum members methods to get mountains and tunnels looking the way I liked. I really like tunnels.
The way I did mine is not the way for the faint of heart. lol
Good luck and and most important have fun with it.
Larry
Sorry the pictures are so weak.