Elven Terrain: Concept Art and first steps

So here is the concept art for a few terrain pieces I will be making for a friend High Elf player (nobody's perfect).
Crystal forest and Elven Waystone:

 Elven Tower (that is going to be a real challenge I think):

 I started cutting pieces for the Crystal Forest out of insulation foam:

The next step is to smooth down the 'crystals' and coat them with some sort of protective layer.