Scott Montgomery made the final table of the WSOP Main Event in 2008 as a member of the (first) November Nine. In the latest issue of Card Player magazine (scan of cover above), he was asked what sorts of things was he looking for to spot a bluff.
Beyond reading bluffs is convincing people not to bluff you. That's why having an image as someone who makes crazy river calls with bottom pair defintely helps a lot in tournaments. Pull a couple of those a day, and you'll scare people into not bluffing you.