Back in the days when I started drawing, we depend a lot on our own experiences and there is no structured system of producing our art. So you get a wide range of methods and styles which makes old cartoon and comics really interesting. But these days, the creative content producers are mostly graduates with proper technical background in drawing and their work is equally impressive but the most important part of it all is always finding that particular identity that is specific to that artist.
The use of referencing and human anatomy is important to any artist. Not everyone can recreate a piece entirely from imagination.
I usually ask my students to model a few position to ensure that the drawing of the artist if limited by imagination is not handicapped when they can see for themselves the human anatomy and the natural movement of the human body.
Some are really concentrating and some are pretending to concentrate. After a while as a lecturer you would be able to spot the ones who are not.
I will usually ask them to place their work on the floor where I will have a good overview of their work and I will pick the ones that I think requires some comments or praise. I prefer praising my students over making them feel bad. Nothing is a better motivator than good praises.
To prove my point this is the picture after I praised them, they work harder...(*snicker *snicker)
Students using reference images when sketching a portrait.
Nothing beats a life projection of the drawing process. Fortunately I can draw a big to save my skin. Otherwise my students will say I am an armchair critic.
So here you go...a day in the life of an art lecturer in a public university
credit to 
@sireh