When you are drilling, and you should add some drills to most every swim
workout, swim-golf is a great way to track your progress. Essentially what
you do is combine your stroke count per 25 or 50 y/m with the time it took
to complete. It is a proxy measurement for technique efficiency and you
should try to bring that number down over time.
http://mytriathlontraining.com/2008/04/07/swim-golf-is-a-great-way-to-focus-on-stroke-technique/