I was flipping through the book The Natural Way to Draw by Nicolaides today, and found this instruction in the very first exercise:
Place the point of your pencil on the paper. Without taking your eyes off the model, wait until you are convinced that the pencil is touching that point on the model upon which your eyes are fastened.
...keep the conviction that the pencil point is actually touching the contour. Be guided more by the sense of touch than by sight.
He says this THREE times in the instructions for the contour drawing exercise: "Be convinced you are touching the model". He even puts it in all caps at one point.
I did the exercise per the instructions, and did pause to try to believe that I was touching my subject. In this drawing, it was three glass bottles, and I started at the top lip of the tallest bottle, and paused there thinking about touching it: cool smooth blue glass.
Nicolaides talks later about running your fingers over a surface, first fast and then slow, before you draw it. There is also a bit of luridness about this touching stuff, because he mostly assuming you are drawing a live, nude model. That might heighten the sensations of touching! My glass bottles aren't quite as compelling as touching someone's naked arm, but the concept still worked.
I'm still not sure what, entirely, to make of this drawing from touch idea, but it is really interesting. It does affect how you make lines, and it brings your focus and your senses much more into play as you — or at least as I — draw. In other words, it works.
I'm starting to see how it is really critical to learn how to make different kinds of lines. When you learn how to do that, you can convey touch — a wooly sweater versus a slick leather coat — in a line. And you don't have to overdo it. You don't want to overdo it, and even trying to do it will make you overdo it. But if you are thinking "smooth leather" while you make the line, experiencing the seeing of the line as if you were touching it — you make a smooth leather line. And if you focus on the nubbly wooliness of a sweater, you can do that too. But if you get too committed to trying to show it, you muss it up — like messing up a tree limb of leaves by trying to draw each individual leaf.
There is a sensory phenomena called synesthesia which is not unlike this touching with your eyes idea. Synethesia is experiencing feelings or sounds with colors — like feeling blue, or blue jazz. It is most often experienced as linking letters or numbers with colors. It is not the same thing as touching your drawing subject with your pencil as you draw something, but the two ideas are on the edges of a very interesting landscape.
Anyway — this is a good trick, and it has helped me draw a little better.