Start being cheap! It goes a long way to keeping your house clutter free. Stop buying stuff you want now. Make a list of 10 things you want and give your self permission to buy 2-4 of those things. The trick is that you place a date beside the items you want and after 2 weeks if you still want it you buy it, then buy it.

However I find that after a bit of time you either want something else or you actually find you really didn't want it at all.
Make your wants compete with your needs for priority. Be honest and fair with your self.