This Zentangle tile was drawn with different size tip pens; the smaller tip helps when the pattern becomes smaller (away from the viewer).
And Rounding - darkening nooks and crannies in tangle with ink to give it a more defined and finished look. See it filling the background of a few tangles below (Poke Root, Tipple, Isochor, and Festune).
And here are a couple more Zentangle tiles working with some of the new tangles and tangleations.