When I swim by myself, my favorite type of practice is one where I swim several hundred yards, often drills with various kinds of equipment, THINKING about one or two aspects of my stroke. Then, I take off the equipment and crank out a few intervals, usually a short, descend set, in which I try to incorporate into my stroke all the things I was working on with the drills and equipment. I repeat this sequence of focused swimming...then speed, two or more times in a given practice. I don't usually give this kind of a practice to my Masters team, mostly because I think they're a bit more interested in cranking out yardage. But today I thought I'd try it...and they really enjoyed the practice.