Chinese history - A great tutorial for scratch your own Ming vases. scratch away the paint to reveal blue underneath. You could also do black and clay colors for Greek pottery or do different cultures such as Asia, Ancient Greece, etc.
Super magnified line drawings--O'Keefe connection. I chose this piece because it is a contour line drawing of observed image. I too am drawing pine cones as well. I like the use of line to create the organic composition.