1) Before you do anything else, make sure you save enough money to go home.
2) Save enough to live on for a lot longer than you think you're going to need because sometimes that "sure thing next project" might not be such a sure thing. Save what you think you'll need, then double it. Maybe triple it. Hell, quadruple it just to be safe. This is easiest accomplished by immediately putting all your per diem in the bank. All of it. ALL!!!!
3) Construction site coffee is a toxic substance akin to crude oil which should not be ingested under any circumstances, even if you're exhausted, even if you cut it half and half with hot water, even if you have three creamers and three sugars, and even if you pour a whole packet of cocoa mix into it. Don't do it! You will die!
4) If you're going to be working a ton anyway, you can probably manage with just a studio apartment, an easy chair, and a really good bed (and a tv and an Xbox, because duh)...you don't need everything else so don't waste your time buying a lot of new nice furniture because eventually, sooner rather than later, you are going to have to MOVE when the project finishes and it will be a pain in the ass.
5) Don't bother with re-collecting all your old kitchen gadgets that are back home in storage anyway. You might use them once or twice, then you have to worry about shipping them home when you're done. That said, DO have a good crockpot. You will be too tired to cook any other way.
6) If you're working 60-70 hours a week, it's okay to pay somebody else to do your laundry. Do not waste time or energy feeling like a failure as a grownup because of this.
7) EXERCISE. Because if you eat out 3 meals a day, you will get fatter and more tired and crabby and spend your time shrieking at your coworkers (which they probably totally deserve, but still, not entirely professional).
8) Make better choices when you're eating out all the time. For example, Subway is better than McDonald's and when you are served a plate twice as big as your head, you should probably only eat 1/3 of it...and that still might be pushing it. Stay away from the donuts, and if you have to have one, buy two dozen and become a pusher because if everyone else gets fat too, then it's okay.
9) Find something social to do with your off-time that DOESN'T revolve around drinking with your coworkers, especially if you are a girl and all your coworkers are guys who like to go to Hooters and Tilted Kilt (love you guys, but seriously. SERIOUSLY!?). Also, don't turn into a hermit and sit on your couch watching tv and playing Xbox by yourself.
10) If you are allowed "home leave", you should take it no matter what kind of crap everyone gives you about how things fall apart when you're gone. THEY are taking their home leave, so they can shut the f*ck up. If you don't take your home leave, you will slowly go insane with stress and your friends back home will forget you exist.
11) If you are a woman in the construction industry, you need two things: be a hard-nosed bitch and have a sense of humor. But mostly be a bitch. A bitch who is damn good at her job and doesn't take any shit from anyone.
Ta-da. Now you have my life lessons of the last year. Most of them were learned the hard way, but one of my managers told me the first couple right when I got here. I definitely listened on the first one, but didn't do as good of a job on the second as I should have given the current economy. As for the rest, now I know what to do if this kind of opportunity ever comes along again.