I was reading up on how layouts work 'cause that's the one bit that still really confuses me, and also because I'm beginning to incorporate traditional animation more and more into my cartoons.
http://www.animationmeat.com/pdf/televisionanimation/HB_LayoutNotes.pdf
https://www.awn.com/animationworld/animation-layout-graticule-field-guide-and-labeling