It is never to early to start teaching about the principles of design and the elements of art. Kindergarten artists discussed LINES and PATTERNS before using Sharpie markers to draw a heart and fill it in using as many different types of lines and patterns as possible. We used liquid watercolors to paint the hearts. It is hard to see in the photographs, but I added pearl medium to the paints so that the hearts sparkle festively!
(I often hesitate to show an example of finished work because some artists feel that their work needs to look exactly like mine. In this case, I think having an example to refer to helped the young artists with getting the size of the hearts right and gave them some ideas for different types of lines and patterns.)