These drawings are from an adult art appreciation class that I teach in the fall.  Most students feel they cannot draw.  I have them draw an apple.  Then I give them a simple 10 minute lesson.  The drawings are in order, first no lesson, then students are given the lesson and a real apple to look at.  The third and final drawing students are given colored pencils and a little more time.  Look at the difference 1 hour can make.