Side-by-side portraits using same reference.
Left: 1-minute “blind” one-liner. Looking only at the reference (never the paper) I move the pen without lifting it. This involves “guessing” when the contour is completed.
Right: 5-minute sketch using blue watercolor pencil. Lots of looking back and forth from reference to paper.
I hit both sketches lightly with water washes. The paper I was testing was highly absorbent stock not meant for this purpose. It was friable and broke down like tissue paper when worked.