1) Stop the mail if you'll be gone for more than a week or two. Bring a set of orders to the post office if it's over 30 days.
2) If you don't have a security system, get one! I learned that the hard way.
3) Set a timer on a lamp somewhere in the house.
4) Unplug everything else.
5) Close all the blinds
6) Set the thermostat appropriately.
6) Hire a lawncare guy to come every couple weeks if it's summertime.
7) Have someone swing by every week or so to start the car (if it's there) and check or busted pipes, and pull the religious flyers off of your front porch.
8) Get a safe, or hide your valuable stuff someplace your common thief wouldn't think to look.
9) Get as many of your bills as possible set up for online payments. Bring checks and mailing addresses for the rest of them.
This has all worked pretty well for me during 2 deployments and many many TDY's.