These are 2 of my 30 minute studies, where I didn't like the colors in the first one, and did the same design, but with different colors.  I like the simple design, and that's really why I keep the time to only 30 minutes.  You can't get too detailed when there's a limited time. This design will be the start of many paintings to come.  By the way, these are done, using Tombo markers.  I found that watecolors were too slow for my 30 minute time frame, so I work with the markers, very much like I paint with watercolors, still building up to the darks, and glazing to get new colors.