I sketched this scene tonight on the front porch while Gina planted flowers. I referenced from a book called Beautiful Britain for the landscape and made up the heads in the foreground.
I actually used some Derwent watercolor pencils, which I don't really enjoy, and some little Elmer's Brand brush pens for little kids. They are filled with watercolors that aren't too bad. In the heavier colors I dumped some of the paint out and replaced with water to dilute it some. Beinfang does make a nice set of watercolor brush pens that are already filled but I don't feel up to spending the $20. I will most likely just end up dumping most of these little pens, which were free, and mix my own colors to put in them. If you're not careful though, you can oversaturate the fibers of the paper resulting in blotchy spotting on the opposite side of the paper.
The black was achieved by a Sakura Brush pen/marker. I recommend this marker for drawing on the go. You can get some nice brush stroked and bold blacks with it.