I am always going on about getting rid of stuff, but sometimes you really do need to keep things around. I will admit to keeping rubber bands, disposable chopsticks, gift boxes boxes, etc., because I really do use those things all the time (I swear). The only way I can keep them from reproducing out of control is to set very clear limits on how much I should keep. If you don't corral things they will just take over and you will end up with a truly ridiculous amount of stuff.
Let's say you want to keep some gift boxes. Chances are you have lots of them left over from holidays and birthdays, but you don't want to throw them away because they seem so useful. Before you haul out all the boxes you have, stop and think about how much space you are willing to devote to keeping them. A shoe box? A drawer? A storage box? Once you decide the amount of space that is practical for you, don't allow yourself to keep any more than will fit in that space. And be reasonable with yourself. If you say you need to keep a refrigerator box full of them even if you only ever give gift certificates, that's just silly. If you are in doubt, always go for keeping less because it's not like those things are made of solid gold and you'll never find another one.
The nice thing about this approach is that if something nicer comes in, the least useful/attractive thing gets to find a new home, and eventually you will have only the cream of the crop.
Let's take a moment to admire some organizing success. This person's gift box collection fits only in this storage container, and whatever doesn't fit has to go. Brava.
