A few years ago I went through our house and removed a significant portion of what we owned. Almost all of our books left (and went to a good cause) and I sorted through housewares and clothes and art supplies and donated what I hadn't used in the past eighteen months. The proximate reason for the clean-out was that I was having the floors replaced in the house but the ultimate reason was that we were burdened by our stuff.
I organized what was left so that everything had its place and I vowed to be more mindful about what entered the house. Over the last two weeks I have swept through the house again, evaluating every object for its role in our lives. I am pleased to report, that with the exception of a few notebooks (do they breed at night?), I have been successful in holding the line on what we own. Everything is put away, there is still space and I can recall using almost every item in the last year or so. The exception is the kayaking gear but we will get back to that when I stop leading a cycling group.
I was helped by reading the book Clutterbusting by Brooks Palmer. It isn't to everyone's taste but if you want something that is more about the why than the how-to, I recommend it highly. The author also writes a blog which I haven't checked recently but did read regularly when I was in the throes of making the big changes at home.