Be careful of drawing hard outlines around your objects. Instead, pay attention to the difference in value between your object, the background, and the surface it sits on.
Pay close attention to the values (light and dark) of the object.
Cross contour is NOT cross hatching. Cross hatching uses perpendicular marks to create dark value. Cross contour follows the planes and curves of an object to both depict shading and volume. If your marks do not follow the planes of your objects, please review Professor Fahr’s video so you understand the important difference.