/ic/ - Artwork/Critique

How to get a improve my inking with pencils ? I'm using some faber-castell pens with brush tips, which in some cases give nice aspects, but as far as "filling" goes (as in the drawing), it can get messy (which it did). not satisfied with the train colors and roof in general, but I got lazy (focus was on the characters, but could have done with more colors on the White-red rabbit Commissar) General comments welcome.