This ugly blue thumbnail sketch was created in Photoshop with my Wacom tablet.
I then used black to draw on top of the blue. My goal here was to find the best lines from that blue mess above.
Next, I printed out the digital sketch and traced it on my light-box. The characters continue to evolve. I like my Wacom but it can't beat pencil and paper at this stage.
I rescanned the image and traced it again in Photoshop. At each step I continue to hone the characters, background and details.