What's your go-to building trick that most people miss?

I've been messing around with a new survival world and trying to build things that don't look like a box. Found that using stairs instead of full blocks for window frames changes the whole feel. It's a small thing but it makes a difference.

What about you? Got a building tip or trick that you see people overlook all the time? Could be for houses, terraforming, interiors, anything. Drop it here and maybe we all learn something.