My favorite form of drawing, what comes most natural and is the most pleasurable for me...has always been the looseness of drawing off the cuff. Laying down NO pencil sketches, no tracing over preexisting lines....just going right at the paper with pen in hand and working through the improv of what goes from my hand through the marker to paper!
Many artists/cartoonists will tell you their pencil sketches are the favorite part of their work because the inked over lines never retain the loose, action-filled expressive line that comes from throwing down those first unhibit lines of a rough sketch. I can tell you that my own illustrations that are finalized by going back and inking over my pencil sketch aren't near as loose, fun or spontaneous, in my opinion, as my off the cuff work. __So, when I have the chance to sit down and just let pen go straight to paper, I'm as tickled as anyone to see what turns out from the spontaneous flow.
The illustration below is an example of pen (marker) directly to paper. I created this, this afternoon when I got home from my part-time gig and just needed some creative time to unwind. It started with no particular idea in mind, I just drew the nose (which turned into the bear) and improvised from there. The illustration created itself pretty quickly, and that's the magic of drawing that I enjoyed as a child. Pretty cool to still be able to experience that child-like joy...at my age :-)