Clever use of light (OK, all photography is about light, but some are able to use it better than others)
Photos mounted on/in black.
Offbeat composition for its own sake that does nothing for the end result. (Anyone remember the 'STARB' obsession? Shot Through A Rhubarb Bucket?)
Anything starring a windswept, gnarled tree (every other photo of Dartmoor seems to have one).
The use of colour filters in colour photography, e.g. graduated filters for skies. Polarising filter, OK, graduated orange filter, not OK. No logic - just the way I feel!
People who brag about how many 'bricks' of film they've bought/got in their freezer. I am not interested - it's what they do with it that counts.
Photos mounted on/in white.