Now that the black and white outline is established the second step is to add some color. the process i go through is creating a second layer in illustrator directly behind the outlined picture.
the top enlarged box shows the same details as step one did the only difference is that its colored further along in the process you can add shadows and light areas on the dragons body, foremost the eyes.
The second box shows the dragons wing and the difference between the front and inside of his wings, many details can be added to the dragon to show off. lowering the opacity of the wing is an effective way of showing a thin twat wing
Step 3 will involve shadows and eyes