I have all the above problems with head retention. Certainly a good clean glass rinsed before filling helps. Also have used Cara Pils, Torrified Wheat or rolled oats in various brews which helps too.
I wonder if it also has a lot to do with the dispensing nozzle. i.e. a real ale is delivered at very low carbonation but often pushed through a nozzle on the hand pump which creates a fine head with very small bubbles. When I pour a pint from my keg fridge I get a nice head but the bubbles are releatively large compared to those created by a hand pump.
(By the way I'm disgusted by all the morons who think they are being funny and have almost wrecked this interesting and relevant thread. Far too much of this on this whole forum for my taste
)