Here are more sketches I did, while trying to "get to know" a certain character in my next comic a bit better.
I would say that, ideally, a person should be able to "fluently" draw the characters they create from any angle necessary. This requires much preliminary work, such as drawing said character over and over again until you are able to get it right.
When I find that I have created a drawing that appeals to me, I will often ink it on a clean sheet of bristol board using a lightbox. Sometimes, if this is too cumbersome, I simply use rag vellum, which is like an ink-friendly tracing paper. I then use Photoshop to add tones and/or colors.
I often just scribble until I find a line that works.
The drawing below left looked too much like a man at a urinal--it was too static. I needed to capture a pose of my character in mid-walk.