I've read about the "one in, one out" policy in the past. This is where a person (or a household) decides to curb stuff by deciding to get rid of one thing for each new thing that enters the household. This is typically done with something that the person has "issues" with and the person replaces like with like -- clothing, shoes, books, albums, cat figurines -- anything that's threatening to become excessive.
Whenever I used to think of this concept, it would scare me. That's right -- it would scare me. The idea of having to get rid of material goods in order to get more material goods was terrifying. "What if I'll need something in the future?" I thought. "But I love those new shoes just as much as the old ones -- I want both pairs!" I told myself.
But just the other day, I needed new sneakers -- really needed them. My eight year old sneaks had a hole in the sole. So I went to a thrift store and got some nearly new ones for ten bucks. I took a little stroll down the skirt aisle and saw a lovely white linen skirt. I'm a big fan of white linen skirts. I thought, "this white linen skirt is nicer than my current white linen skirt. I'll try this one on, and if it fits, then I'll have two white linen skirts, great!" But all of a sudden it struck me -- why would I need two? For absolutely no reason. And then I got it -- I understood the "one in, one out" policy. I have every material thing I could possibly ever need (except a Scooba). I am having a tag sale next week to get rid of excess stuff and I have vowed not to get to the point of having excess stuff again -- so why would I buy another white linen skirt when I already have one? Well, this white linen skirt was newer, nicer and fit great. It cost $4.99. My old white linen skirt probably cost about that when I got it five or six years ago and it shrunk a little such that the lining was showing. So I decided to get the new skirt and promptly put the old skirt and old holey sneaks in a bag to bring to the thrift store (will anyone want holey sneakers?).
And the "one in, one out" policy has begun and is unidirectional. I can certainly put one out without bringing one in, but when it comes to clothing, shoes, and housewares (not books, which I don't consider consumer goods), when I buy a new one I will put an old one out. And if the thought of having to get rid of something in order to get the new one bothers me, I'll put the new one down and walk away.