As promised the steps I took with my dog assignment:
After a quick sketch of the 'real' dog (muscle structure in plaster stone) I constructed the skeleton. I worked out the first traditional pencil drawing for my assignment.
As a next step I put the drawing of the skeleton in the context of the outlines of the dog.
While I did the first parts partially at home I worked on the full drawing of the dog in school.
When the drawing of the plaster dog was finished I did the same as with the drawing of the skeleton just the other way around. I made a digital version of the skeleton drawing and put it on top of the drawing of the dog.
And finally the digital version of the skeleton (which certainly was the hardest for me to make because I never made such a complicated drawing in Illustrator).