For houses I mainly use Spruce wood, and to add some detail Oak fences or Spruce Trapdoors. When im building modern houses / buildings I prefer to use White concrete, mixed with black stained glass. When I build things like ruines I like to mix different blocks like mossy cobblestone, stone brick walls and cobblestone slabs. When im making paths when im terraforming I mix blocks like coarse dirt, grass path blocks and other blocks like gravel and andesite. I think it really depends on what style you are building with, and what size your building is going to be. Sometimes you need to do some expirimenting to find out what works best for you :)
I hope this helped, good luck!
