Get ahead of that mad dash to the tracks
Amtrak’s Northeast regional trains from Boston stop in New York before heading on to DC, watch the arrival board for the Boston train; that’ll be your track for the outbound DC train, too. You can get ahead of the herd, and keep a modicum of sanity. Also, trains to Albany routinely depart from gate 5, 6, 7, or 8, so you can hover nearby and get in line faster when the number is announced.
You don’t actually need to print a ticket
Unlike the Port Authority, here you don’t need a tangible ticket. If you feel more comfortable holding a ticket, you can use one of many Amtrak and NJ Transit machines to purchase and print one on the spot. If you’re in a rush, however, and don’t want to wait in line, book your tickets with the Amtrak app or NJ Transit’s MyTix app. Make sure to take a screen shot of your ticket in case you get kicked out of the app (it happens), and because NJ Transit’s app drains your battery. The apps have the added benefit of allowing travelers to buy tickets onboard, and you can check the arrival and departure status of Amtrak trains.