Drawing open shapes takes less time than filling everything in. That might be affected by my choice of pen, but I am too much in love with the Pilot Precise series to give it up now.
Originally, I wanted to create something I could draw quickly, then fill in later. The first Open Landscape was all right, but I always knew there was more to the story.
This came next, and I drew it on a larger canvas, then blew it up further and colored it in with markers.
The results were slightly disappointing, a riot of color to no obvious end.
My father received it as a Christmas present and framed it! (Briefly.)