I have tried a new approach today. I did a rough sketch in pencil first, then I did refining and coloring with colored pencils, and last step was outlining with black pigment pen. It is quite different and black is not softened up as it sometimes is on previous drawings.
I've learned some new things and I'm satisfied with the end result :)
After showing it to my close audience I got a comment: "According to the face expression I know exactly which part of the book he's on now."
@cutedicta you may like this one :)