I work 12 hour dayshifts, and getting through two twelves in a row is all I can muster. I'm a zombie by the middle of the second twelve hour shift. A snicker's bar, a cold bottle of water, and something to laugh about help me get through the second twelve hour shift.
My first day off after working two twelves in a row consist largely of rest, rest, and more rest the majority of that day. Later that afternoon, I go out for a meal, run a few errands, and make sure I'm home early enough to rest, rest, rest some more.
By the time I have to return to work to do another 12 hour shift, I'm semi-rested, and keep telling myself "This day will end, then I'll be off a few days." Whatever gets one through those long painful shifts is worth trying.