The security holograms on banknotes sparkle wonderfully when lit by a single flash placed close and simply moving the flash so it shines at a different angle across the face of the banknote changes the image dramatically.
For the 1 pound coin I was trying to use selective focus to exagerate the image of the bridge and distance, a bit fiddly considering the size of the coin and that I was hand holding the coin (see here for official details of the coin).