1. Stop buying stuff you don’t need
  2. Pay off all your credit cards
  3. Get rid of all the stuff that doesn’t fit in your
house/apartment (storage lockers, etc.)
  4. Get rid of all the stuff that doesn’t fit on the first floor of
your house (attic, garage, etc.)
  5. Get rid of all the stuff that doesn’t fit in one room of your house
  6. Get rid of all the stuff that doesn’t fit in a suitcase
  7. Get rid of all the stuff that doesn’t fit in a backpack
  8. Get rid of the backpack

 (from here: http://diveintomark.org/archives/2008/11/03/the-pursuit-of-happiness)

 And while #2 isn't the sort of thing you can do immediately once you
get to a certain point down the rabbit-hole, if we discount that as
"working on it" I'm currently oscillating between 5 and 7. About 30%
of my time lately, I live quite happily out of a backpack, and the
rest of the time I'm nowhere near outgrowing a single room. Compared
to most of my life up to this point, this is shocking if I really sit
down and think about it, but a very good thing.