The Diva's weekly challenge was to create a Zentangle and not fill in every little space. I must admit that can be a challenge when you are tangling. I often have to consciously make myself leave negative space, but I I seem to like the tangles I create with white space much more. Though you can fill in every space of the tile with pattern and still have white space by carefully choosing which patterns you use. Some of them leave a lot of white within their design and this serves the same purpose compositionally.
At any rate here is my tangle of this challenge: