DS:
always puts dishes across two dividers (so, kind of diagonally) in the dishwasher.
Cleaner:
doesn't scrub taps properly, leaving limescale mountains.
puts the mop's head inside the bucket once she's finished, not on the litle basket, so it remains wet
Many other people, including bf and BIL:
wash meat [grr]
BF:
keeps turning water on and off during a quick shower, supposedly to save water/gas I think
Lab students:
don't pay enough attention to contamination sources and behaviour
Other drivers
list too long to mention (e.g. no indicators, going right to turn left, roundabouts, parking, dropping children at school, driving in the middle, no lights during fog, ...)
women in public toilets:
hovering. Just fucking sit and don't splash the seat.
I'll think of a few more later.