Don’t measure everything first.
I am cheap, so I build my dollhouses from scratch. That means I either draw out the plan before-hand, or I have to improvise as I go. This time, since I was using a plan that I had found online, I decided to draw out all the panels, and cut them first. I figured this would allow me to make the best use of the plywood I bought, and it would be faster in the long run. It turns out, this decision took a considerable amount of time, and I wasted most of the wood.