“Focus your eye on some point––any point will do––along the contour of the model,” Nicolaïdes wrote. “Place the point of your pencil on the paper. Imagine that your pencil point is touching the model instead of the paper.” Once you’re convinced that the tip of the pencil is synonymous with the sight of the eye, Nicolaïdes told artists to begin to slowly follow the contour of the model across the surface of the page. “Be guided more by the sense of touch than by sight,” he instructed.

Source: Blind Contour Drawing Can Help You Become a Better Artist – Artsy