I've read a lot about proper running form, and even taken some classes, and they helped. But the biggest thing is understanding. This video, on Running Times, is so clear and easy, I actually get it. It helped a lot with today's run. When I was getting tired today, running a little longer than we have been, I'd just do the tricks, clean up my efficiency and the oncoming soreness would go away. It gets harder as you get more tired, but it works.
http://naturalrunningcenter.com/2012/03/06/video-the-principles-natural-running/