Zentangles seem to be all the rage lately.  I keep seeing them pop up all over Pinterest and other art education sites. Here is just one example of Zentangle artist trading cards that I found on a Pinterest board.   I've even heard them to be "yoga for your brain", which I thought was really cool!
As my 6th grade students started up art a few months ago, I wanted to remind them about the elements of art.  I thought Zentangles would be a great way to talk about the use of line.  Rather than doing a straight up Zentangle, we first sketched living things...animals or plants for the most part...that happened to have natural patterns in them.  We then put our line and shape patterns inside the natural patterns of the living things using black Sharpie markers.  As a final touch students used colored Sharpies in either the animal or the background to give it some contrast.  They worked hard on these and are very proud of their finished work!