I happened to run into a entangling sample by Lydia Fiedler, and I just had to try it. Unfortunately I didn't have a sharp enough marker (a fellow demonstrator suggested using the Project Life marker, mine was just your regular office version).
All the Zentangling samples I have seen, are beautiful. I think mine became a bit too busy and I'm not at all sure if I have the patience to sit still long enough to do all the zentanging :-)
My card's background is done with Work of Art stamp set.
Here is Lydia's Zentangling tutorial
Enjoy and have fun!