Like many said before, wash inside-out in cold water then either dry on a rack, or dry in the dryer on air dry or "fluff". It takes a while, but they don't shrink much, if at all, that way. Also, doing squats and lunges helps to stretch them out, along with just sitting for a while. So put 'em on, flop down on the couch and watch a show for an hour or so.
