For double height walls, Build a full wall piece down, then snap next to it a half wall, then aim at the top of the full wall, while standing on the half wall, and snap in place. Or, build stairs so you can aim ''above the snap point'' of the first full wall. (if that makes sense) Probably better to just check out a few guides on building. There are some really talented builders out there, use them for your own inspiration.

Another thing I recommend that is easy as pie to make is a pit house, just dig a hole in the ground (preferably higher up, away from water) and simply slap a roof on top of it. Very easy to build & affordable, & cuts down on building materials needed to be gathered to construct at the same time, as the earth itself are the walls.