Never make eye contact…
Do not, under most any circumstances, lock eyes with someone else on the train. If you accidentally make eye contact with a “normal” New Yorker, they will instantly shift their gaze away. But if it’s a “crazy” New Yorker, eye contact is like an invitation to their crazy. You could be attracting the attention of a Bible-verse spouter, panhandler, romancer, creepster, or just someone having a bad day who wants to take it out on you.