If you have never been to a swap party, here's a solid life tip for you: Go to one. Or host one. Because what will happen is you will clear out all that stuff in your closet that you don't actually wear, and possibly replace it with stuff that you will.
But throwing a swap party isn't actually as simple as "invite people over and let them trade stuff" - it works much better if a little organization is involved. When faced with the prospect of owning cashmere sweatshirts and designer bags that they do not have to pay for, people tend to do better with a few rules.
These are mine.