Lines are results, do not draw them for themselves. ... Lines give birth to lines. Drawing is not following a line on the model, it is drawing your sense of the thing. ... Make a drawing flow, stopping sometimes, and going on. ... Search for the simple constructive forces, line the lines of a suspension bridge. Get the few main lines and see what lines they call out. ... Have purpose in the places where lines stop.
Robert Henri
art, composition, line