Originally posted by WhamyKaBlamy:

Something I also found useful was to take over those stone buildings you see. It takes very little effort to board up a few of the holes and put a door on the front. If you build some stairs inside, it can be a nice little sniper tower to take out trolls.

Yeah, You can also through core wood poles of the top in every direction and frame it out. Counts as grounded. I've converted a few of those into massive portal forts.