The first is a contour drawing with minimal detailing of my white Subaru, "Belle." I don't usually draw cars so I think the contour drawing process helped me see it more correctly and get it looking pretty close to real. The squished front end comes from drawing the car on two sheets of paper and then tacking them together. Sometimes with blind contour drawings you simply lose track of your paper and need to add more or leave your drawing only partially completed.
Contour drawing of Belle
The second drawing is of a fairly complex tree shape in my backyard. Again a contour drawing with minimal details.
Contour drawing of tree
Both of these drawings could definitely profit by the addition of some color. I left them monotone deliberately just as I also left them with only minimal contrast marks, simply because of the nature of the exercise. Simple lines, not much else.