When you look at a wall spotted with stains, or constructed with a mixture of stones, try to find a scene. [Similar to cloud-watching]. You may find a resemblance to various landscapes, beautified with mountains, rivers, rocks, trees plains, wide valleys an hills. Or you may see battles and men in action; or strange faces and costumes. You may take this interpretation of what you see and then try to draw it in a finer, more detailed form.