Or I'd do projects like paying attention to corresponding fingers and toes, but not with the sort of dedication where the projects would be likely to make any difference-- they were an effort to avoid boredom.

Actually, "just paying attention" is believed to be able to make a large and lasting difference. I can immediately adjust my posture, in various ways, by focusing on different points on my body. Without voluntary contraction of muscles, the muscles adjust. In fact, adjust much better than if I try to "do it" voluntarily.