If the square has you confused, shoot as much as you can. Either it will start making sense, or you'll be looking for a 6x4.5 back.
And when not shooting, look at people who have used it.
A couple of people not named-
Michael Kenna- http://www.michaelkenna.net/imagearchive.php
Lee Freeidlander- http://whitney.org/Exhibitions/LeeFriedlander/Images