When you work to clear the clutter from a space, I recommend that you sort objects into three piles: keep, purge, and other. The keep pile is filled with things you plan to keep, the purge pile is filled with things you wish to get rid of (trash, recycle, donate to charity), and the other pile is for things that require additional action (return to library, take to tailor to be hemmed, take to cobbler to be resoled, etc.). Unfortunately, there is usually a fourth category of items — the tough calls.
I’m of the opinion that it’s okay to keep tough calls, at least in the short term. When it comes time to put things back to their permanent homes (a place for everything, and everything in its place), you’ll know if you have space to store the item. If you don’t have space, get rid of the object. If you have space, put the object in a box and seal up the box with tape. Write the date on the top of the box and what you would do with the item if you got rid of it (sell on Craigslist, give to Aunt Lynda). At some point in the future, six months is usually a good length of time, if you haven’t opened the box just do whatever the directions on the box tell you to do. Except for items you plan to sell, you don’t even need to open up the box and look at the item before getting rid of it.
As far as tough calls are concerned, I’ve found that they reduce in number the more uncluttering you do. The temporary holding box is a reassuring safety net when you’re first getting your footing. I think it’s an excellent way to help others ease into uncluttering, too.