This site has a really easy way to do it:
http://www.taospaint.com/Tessellation.html . I have
used this with first and second graders. I just have
to adapt the objectives down a bit so I stay within
their range. I teach K-12 and it gets interesting
adapting things out but this lesson is one of the
easiest to adapt. You just have to like working with
the copy machine a bit....lol.