The way to get really good at it is
to let a few trains pass, note where the doors arrive at and average them out. Then wait for the third and be confident about it, not forgetting of course the single hand motion to "open" the doors.
( buffet_the_appetite_slayer ٩(●̮̃•)۶ jacked in to the ICE on, Sat 17 Dec 2011, 18:08, 1 reply)

Unless I'm mistaken
London tube trains seem to always stop at the exact same spot, so if you remember where a door was once you're set for life.
( Zoroastermouse thinks therefore he am, Sun 18 Dec 2011, 0:37, closed)