I have been watching the excellent "Terrain Tutor" videos on Youtube. I clicked on a suggested title called "Black Magic Craft". This series is produced by a guy in Winnipeg. He makes lots of sweet looking fantasy terrain for his DnD games. He uses insulation foam which is easy to work with and cheap. I bought a couple of foam cutters off Amazon and a bunch of foam and voila!
This cutter works great. I am excited about the possibilities this baby can produce. I also bought a cobblestone mat from Michael's with the hope of converting it into roads at some point. I trotted out all my 28mm buildings for a photo op.