"Get back here, Calcifer! I'm still cooking breakfast!"
Howl's Moving Castle is one of my (many, many, many) favorite books--sorry to all you movie people, but I'm definitely a book purist!--so it's kind of surprising that this is only the second piece of fan art I've done. (We'll have to fix that.)
I scanned my inks and decided to color it the lazy way! I ran the GMIC colorize lineart filter in Gimp which gave me a wonderful patchwork of colors, then used the fill tool to combine larger areas of color and define shadows in Sophie's dress and hair. I selected Calcifer and colorized him, which unified the colors, but kept a variety of values. (Calcifer is two layers--a blue one and a yellow one, with layer masks to blend the two together.) I finished it off with an ink-and-tea texture I made recently.