I usually put down some white on the horizon as a sort of value check, I know that I will have to keep that area extremely light. This works for me because I usually don't have time to labor over the sky when I am in the field, at least on the first day. Later when I do my tweaking at home I mix some patchy light color spots into that white zone.
Below is the finished painting. Other than the biting gnats, the afternoon was peaceful.
|Rotoballe Sulla Collina o/c 40 x 50cm available at the Stage Door Gallery|