I don't know a lot about comic book art, but I can imitate as I learn. I do know about inking, though, since the process of clean-up for animation is very similar.
First of all, inking isn't tracing! You're re-drawing the image where the pencil lines used to be. Ink style is a lot different from pencil style. With ink, you are laying lines down much more deliberately than with pencil. The phsyics of ink demand holding the pen or brush differently than a pencil. Pens in particular require a careful approach because ink from a pen dries much more slowly than ink from a brush, so pen ink invites smudges. However, it can take months or years to learn to use a brush well.
Animation clean-up seldom uses ink, but the principles are the same: you draw so slowly that it becomes nearly impossible to make a mistake, as long as the penciller has made no errors. It requires an extremely steady hand and powerful, extended concentration to do it well.
More and more, ink and clean-up are done digitally, as I have done with Sylvia. The bonus is that you get an "undo" button. With real ink, you end up fixing mistakes with white paint. I remember seeing a Japanese manga artist at the Vancouver Art Gallery who admitted to whiting out his lines and inking them back in twenty times without a second thought. If you looked at the page edge-on, you could see the mound of accumulated white paint like a big old blister sitting on the paper.