The main thing with building is understanding how the game decides on the level you are working on. When you start with your uprights, be sure they are blue. If they are seen by the game as sitting on a wood floor piece they will be green. This makes for many of the problems when only building a couple floors high. If something is not working, or part of a wall is turning red when everything at same level is orange or yellow means you have failed the first test, starting with you timber touching ground. Or as some will point out... The first piece of wood coming off a piece of stone will also be blue.
There are many ways to fiddle building in the game but first you have to understand how it works. Building your skeleton first is the best way until you get a bit of experience, then you can be more free-form. But it's like everything else in this game, being careful leads to better results. And I always say that most of the really fancy builds we see are made in free-fly mode. Only then can we defy gravity.