I drew another picture, this one is a chess piece in 3D. It has proportion and background rhythm.
Proportion:
This has good shading, you can tell this has a 3D effect and I made that by using good value skills. I used light to make sure it's accurate and be able to identify the dark and light spots.
Background Rhythm:
The background rhythm shows chess pieces, the one to the right is the closest to the viewer and the one the left is the farthest one. It show rhythm by repeating the same object which makes your eyes move in the direction I want you to >:D