Simplicity in a Zentangle tile is not always an easy thing to achieve. One of the things that is so fascinating about Zentangle to me is losing myself in the tangles and just going on and on. So for this challenge I had to force myself to think about tangles n their most basic forms and to stop early. So, I stopped - but then I was really into tangling mode so I did one tile after another. The one at the top left is a simplification of Zhostovo Border. At right it's Striping.
This is Aquafleur.
The tile to the left is Gneiss. To the right is a combo of Ditto and Flux.