Ditto to what MG Singh said! However, half the fun of being in a new place is acquiring new things specific to the area, so be sensible about your purchases.
I also agree with sunbun 143 about framed family photos and big rubber storage bins. I took the family photo thing one step further and acquired a few frames that have a two-page photo album in the back.
The best advice I can add, though, is settle on a decorating style and furniture arrangements that'll work anywhere, and **condense, condense, condense**. Frequently-transferred military families have this one down pat. Confine decorating purchases to items that can do double (or triple) duty. For instance, a footstool that doubles as blanket, game or DVD storage. If you have a lot of books, get stackable cubes that can double as book shelves AND book carriers at moving time, so you don't have to re-box the books. Also, furniture that breaks down easily or fold up. Under-the-bed containers for out-of-season items save packing at moving time, too.