When pruning a wardrobe, the classic advice is to make three piles: keep, alter and discard (via donation, gift or resale.) This system works, but you need to be in the mood to make a certain, swift decision.
If you are not sure you'll ever wear that purple silk blouse again (and it fits), or if you have somehow amassed a dozen pairs of dark pants and aren't sure which ones to keep, I suggest the Furlough Method.
With the Furlough Method, you avoid getting swept into the thrall of purge passion, only to find that
the cost of another aqua cashmere cardi—which you now realize would look
great with your new charcoal skirt—is a lot higher than what you paid for the one you gave away.
Step #1: Make sure it's clean (you don't want to raise a farm team of moths), and pack in a garment bag or box. Store the piece out of sight, and not in your own closet, where you might be tempted to peek.
If your memory is not perfect, like mine, make a list of these items and where they are.
Step #2: Wait a minimum of four to a max of twelve months. One of two things will transpire:
A. You discover that you miss the item: Take it out of storage and wear it immediately– that's why you dug it out, right?
If the item makes it back into your closet, apply the Hanger Test.
After that first wearing, turn its hanger in the opposite direction to
the rest of the garments. If in four months (or a season), that hanger
is still pointing the other way, get rid of it.
No, you don't re-furlough; that would take you to the territory of nutbar-hoarderland.
B. You do not wear or even think about the thing: Out it goes! (If you can do so without looking at it again, that's best.) At this point, parting feels entirely different than pitching it in the initial cleanout stage.
In the past, thanks to my mother's influence, ("What? That skirt is perfectly good!") I could eat pufferfish liver with more equanimity than cast an expensive item from my closet. Post furlough, the item loses its emotional power and I can let go in peace.
You could achieve the same thing by loaning the piece to a friend for awhile, with clear repatriation rights and an understanding that there might be some normal wear.
In the world of pretty new things, this Etro dress, audaciously Italian-ly springy as a park full of tulips, turns my head:
I don't think that dress would ever leave my closet!