A years-long, on-going practice, I've been using the tradition of plein air painting as a meditative ritual that informs all of my work. This was a natural extension of the repetitive, observational nature of the Pieces of Sky project.
These studies are done mostly outdoors, on-site and in the moment. I have chosen a number of constraints, including watercolor as the medium, 6"x8" paper, and no more than one hour on one study. I choose locations that are considered "in nature" but shaped by humans. I often don't know what I will be specifically seeing or where I will choose to stop and observe, but I prepare for the day's conditions with the proper supplies, food and clothing.
The sites I choose are usually sheltered from the wind and sun, but offer what would be considered a "vista". The sites also must accommodate my body so that I can sit or stand comfortably for about an hour, so I have to choose carefully. I occasionally return to the same site multiple times over the course of years. The timing must also be just right, as the noon day sun is often too harsh for too long, but the light changes too rapidly at the end of sunset.
Acknowledging constraints and the process is just as important as the act of painting.