Sounds simple enough right? Don't be fooled: this question is powerful if you answer honestly.
Here are two ways you can tell if an item hanging in your closet serves you:
1. Does it make you feel good when you wear it? Or, are you excited to wear it? Lukewarm reactions are exactly what you don't want here. Let it go. Try it on if you need to, and, even better, have an honest friend (the one you always bring into the fitting room with you) there to give you honest feedback when you get stuck.
2. Do you actually wear the item in question? When is the last time you wore it? If it's just taking up space and you can't remember the last time you put it on (if ever), it's time to part ways. Anything with tags still hanging on it, dust collecting on its shoulders, or waiting in the "way back" because you swear you will lose those extra ten pounds is what I'm referring to here. If it falls into those categories, it serves no purpose. Let it go.