This Henna Hand Designs Art Lesson shows you how to create a unique and unusual self-portrait of your hands! because it allows them to learn about:

other cultures
the role of pattern in abstract art
how to create abstract patterns
how to express themselves in a symbolic way
It's also a fun art project for adults for the exact same reasons!

First I'll give you a bit of background info about henna, and then launch into the art project.