Stability system:
Blue is best and begins by touching the ground. 5m core wood poles are the best foundation pieces, or giant stone blocks (also resource efficient). You can keep them blue a good ways up by touching other pieces with verticality like walls or the inverted angle pieces for side supports which looks nice and helps on the triangle style. You can use core wood and stone blocks to clip into many wall structures even with a grid snap and reinforce them solidly this way.

Then it progresses through shades of green, yellow, to red, then crumbling in the air.
Don't sleep on 26 degree roofs instead of 45, I had a ton of trouble doing square buildings before I learned this, they are a lot easier to work with in many situations including emergency cabins for your mining while in combat.