I really like this lesson. It involves skills such as folding, planning, pattern, repetition, color theory and is very popular with the students.
Starting by folding a 12 x 18 in half, then in half, then in half so they can see 8 sections. Each section gets a heart or other shape, each shape is filled with a small repeating shape. The area around the shape is filled with a different line. The lines and shape must be original to each section. Students are encouraged to use different colors for every section.
P.S. The use of sponges on trays is a new idea to keep paints and artwork a bit cleaner, so far it seems to help.