When I pull a late watch (we do 8 hr watches plus OT) I find earbuds and eye masks to be indispensable. You can buy an eye mask at any pharmacy. A lot of airlines offer them free on long haul flights. Grab extras and stuff them in your bag.
I avoid heavy, greasy meals and take a nice hot shower before I turn in. I bring a favorite bag of Hawaiian coffee and a coffee funnel and make my own delicious wakeup cup.