One of the newer Zentangle books out is by Joanne Fink and called Zenspirations. It features wonderful ideas for Dangle Designs to add to your art.
Here are a couple of pages from my sketchbook that I played around with some of the ideas from the book.
I think I'll go sit on the couch now and work a little on my dangles after which a nap is in order. *cough, cough* UGH!