There is a British magazine called "furniture and cabinetmaking". I picked up a random copy at Barnes & Noble more than two years ago - the July, 2009 issue. One article "F&C Technique: Learning with the Barnsley apprentices, report 8 - Hanging a door the Barnsley way", has a one line comment that's been driving me crazy for two years.
"Note that all the screw slots are lined up as is normal in best practice cabinetwork."
The associated photograph is of a flat brass hinge morticed into a door and a cabinet. Each hinge side has six slotted screws in it and all twelve screw slots line up and are parallel to the long edges of the hinge. (Instead of being tall and narrow, these hinges are short - two inch hinge part with four inch long wings.) How on earth do you get these things to: a. have the slots line up, b. have them all tight and holding a hinge to a door.
I posted this question to the website associated with the magazine and nobody there knew the answer either.
Page 47, lower right corner if you have the magazine.