Better to be broadly right than precisely wrong.
Never run for trains.
Always wear a pocket square.
Always be polite to waiters / waitresses.
Always say 'Please' and 'Thank You.'
Hold the door for people.
If you can't spot the sucker in the first half hour at the table, then you ARE the sucker.
Better to keep your mouth shut and be thought a fool than to open it and remove all doubt.
Try never to hurt anyone's feelings unintentionally.
If you don't make yourself laugh, then who will?
He's sure there are more, but that's it for now...