I don't remember the name of the guy (German? Austrian?), but he has videos on youtube.
Basically, his method is this: hook up just one speaker, and position it exactly where you will be *sitting*, right in front of your chair or move the chair and position it exactly where your ears will be. Play some music with some good bass. Get down on your hands and knees, and crawl around the approximate area where you're planning to situate one of the speakers. Perhaps do a grid search. Find the exact position where you can hear most bass. Mark. Repeat, crawling around the other speaker position. Set everything up and enjoy.
On the face of it, this sounds intuitively right. What do people think?
(And you get a little exercise!)