it's not as hard as you might think once you get rolling.
I more or less fit the simple living lifestyle with my possessions as well as my finances.
I'm pretty fixed on the "6 month" rule, if I haven't used it in that long, out it goes. Also with clothing, when I buy new clothes (which I do on a slow, regular basis instead of huge all at once bursts) something in the closet goes to the shelter for every new item that comes in.
I will confess it can approach obsession for some folks but for me, it's just nice not having so much crap orbiting me in my space.
Here's a website dedicated to the concept...
http://www.simpleliving.net/
they have an active and interesting forum that also discusses savings and finances as well as the simple living subjects.