I crop but rarely. With my LF I usually know before I've put the film holder in that I'll be cropping later.
Sometimes my photos are improved (and dramatically!) by cropping but usually a tosser is a tosser and cropping a good photo seems to change it's basic nature.
This may seem a bit odd but.. it's almost like you capture a little bit of the magic of a place and once you crop the photo it just seems unnatural. In reality it is probably just an optical effect I'm too primitive too understand and am hence attributing to the supernatural