Drawing is the very bedrock of representational art no matter what the medium. Drawing helps you see DEEPER and improves the channel of communication between your eyes and hand. The more improved that channel, the more facile you are with your artistic endeavors. I used Sharpie pens to sketch four of my pen and ink students at Sacramento City College (about 15 to 20 minutes per sketch). The were drawn directly with the pens without any preliminary pencil work. With this direct method of drawing and with no corrective opportunities, one needs to look very deeply and and move from point to point very carefully. I did both contour outlining and shading simultaneously. I might add that understanding and controlling value patterns is very, very important. As I moved my pen about the subject, I was cognizant of these visual, right brain items: Contours, Angles, Position of one part of the face compared to another part of the face, Shapes seen in the face, and darks and lights or Values. Remember that drawing is FUN and in my humble opinion, makes you a better artist.