Probably been done before, but here are two to start.
People who eat different components of a meal one after another. i.e. spuds, then carrots, then peas, saving the meat till last!
My next door neighbour is in and out all day and goes through same routine. Gets in Car, starts car, goes to iron gates, opens pad lock, opens gates, supports gates with two bricks to stop them swinging back in(they must be hung badly!). Drives car out onto road repeats previous action. Drives away. Comes back half an hour later. repeats procedure in reverse. This action is performed frequently throughout the day. I don't know why this annoys me, it just does!