When we boondock, it's usually because there is something in that place that we want to see or do such as visiting friends, Burning Man Festival, camping on our undeveloped land in Washington. We walk around, visit with people, work on projects.
If I think I might have time on my hands, I bring a portable hobby like my spinning wheel or knitting. I always have a camera (also waiting for that National Geographic shot that never quite happens) and a book. I like to have something to do, or, better still, options of things to do.