One of the drawing exercises I have students do, (and I'll post some jpegs this fall when school begins again), is work with charcoal vine sticks. Actually, one of my favorite for large drawings.
I work with it while standing, using the loose full shoulder rotation and holding the vine stick somewhat sideways.
I sketch with it on large white sheets of paper, then go over with washes of color as you have done here, and finish by defining darker darks with a #4 Charcoal pencil. I use it to strengthen support lines and some details.
It is not much of a jump from here to use my black ink BIC ballpoint pen for sketching with watercolor washes over that...for which I'm sure some of you are familiar with in my sketchbook Wetcanvas "how-to" If not, I'd invite you to check it out. Quick...easy, fun, effective. http://www.wetcanvas.com/ArtSchool/Drawing/Sketching/
[This message has been edited by lseiler (edited June 28, 2000).]