Since I started illustrating on the computer, it's been a rare treat to do inking and coloring by hand. When I do, this is how I do it.
I draw the illustration with an automatic 2B pencil. When all the lines are where I want them, I erase them out, carefully leaving the slightest impression of where they were.
Then I add the watercolors. When it's dry, I ink in the lines using a 108 tip quill pen, dipping it into Higgens Eternal ink. The 108 is a flexible tip that allows for a lot of line variety.
After this piece was inked, I realized I forgot to put the birds' wine glasses in. So I zapped them in using gouache and acrylic. Oddly, Big Bird wasn't quite right until I added his blue eyelids.
Cookie Monster is meant to look a little dubious. At one point he was going to be pre-heating an oven. I gradually found that he's more dubious when he's less obvious. Something shady may be going on, but it isn't clear what.
And I couldn't resist having him bring the mashed potatoes. Cookie Monster is all about the starch.