Something I never paid a lot of attention to when I was in school was the idea of line mileage. My instructors would bring it up in reference to character designs for animation. "That's a lot of line mileage", they would say. Clearly, I didn't get the line mileage idea when I was doing Mummies. I mean come on. Beside their wrappings they have a crazy amount of detail in the rest of the design.
Now, after 20 years of being a professional artist working in the animation industry with all of the insane deadlines that go with that, I understand line mileage a little more. Just like with a pitcher, every pitch takes a little out of the arm, as an artist, every line takes a little that can't be given back. Twenty years later, that equals a lot of tiger balm, ace bandages and ice. Working digitally, it's worse than working traditionally. When I was working on paper I could hold my pencil in a bunch of different ways. The options are