1: Over complicate things. Ask when trains leave York for Huddersfield. Then ask when the last train will leave Kings Cross to York. Two separate questions. Why not just ask what time they have to leave Kings Cross to make the last train for Huddersfield? 2: Tap their card in a specific way. Seen loads of people turning their card to specifically tap it with the numbers on the bottom, as if they think it won't work with the numbers facing up. 3: Expect doors to open automatically. Many times watched someone waiting at a door while everyone else is boarding. Once or twice the person even walks to another door. 4: Push the door open button before it's lit. It reminds me of those people who flash at traffic lights hoping they'll change, or people who twist the little knob underneath the pedestrian button thinking it changes the lights quicker... I had another but can't remember it right now.