Revisiting something from one of the older books, I know it's not exclusive but bear with me. Some of the sketches that make me happiest are the ones where after I drew them for a few minutes I look back and wonder "how come I hadn't been doing that before." Around here, you can see these in Sketchie Book 3 I think, I started getting a bit more expressive again in body language. I started accentuating legs and arms cause they give an actor better animation especially in still drawings. Course I do tend to favor very stiff stoic figures. But combining that stoic or stable stance with quick bursts of energy could be a visual vocabulary worth exploiting more often.