Getting over the jet lag from the trip home. Usually i manage this buy simply forcing myself to stay awake the entire trip home (not that hard as the seat is pretty uncomfortable) and then when I get home sleep day one to the correct time. It's surprisingly quick turn about. I managed to do it last year as I had to go back to work almost instantly after returning to from Turkey. I have just a tiny buffer this year, but not much.
Coffee, hmmm, maybe Diet Dr Pepper to the rescue.