The new issue of International Artist magazine includes my latest masterclass on serial painting.
I use the term "serial painting" to refer to plein-air painting where several images are created one after another, connecting them through time or space.
One approach is to make a set of closely related studies one after another, like frames from a film or comic book. I learned this from architectural illustrator Dan Church, who paints a set of small watercolors out of the window of a moving car. It helps to work really small if you're working this fast.
The other kind of serial painting involves painting multiple plein-air studies of the same subject under different lighting conditions. This is one of the best ways to become aware of the effects of different lighting conditions.