Lately I've been reading a book called Goodbye, Things. It's similar to The Life-Changing Magic of Tidying Up, in that it's another of these Japanese minimalist culture books encouraging people to get rid of all their things. It's a little more extreme than Life-Changing Magic in some ways, and a little easier to follow in others.
In Life-Changing Magic, the author encourages you to get rid of anything that doesn't give you joy. This means taking every thing you own in your hands over the course of six months or so, and seeing if you feel joy associated with it. If not, get rid of it.
I don't know about you, but I get overwhelmed super quickly when I try this. Before long, everything give me a strange mix of joy-not-joy that I can't feel my way through. Which is why I like certain aspects to Goodbye, Things, even if his overall approach is more extreme.