I do not begin to have the stash many here have acquired. I think that goes back to my years of moving around when my husband was in the Navy and then school. Most of my fabric that lies in limbo has come from my two older sisters who down-sized and passed it on to me. I seem to have a guilt complex about getting rid of it. And, to tell the truth, some is very nice stuff. There are some woolens that I'm not sure can even be purchased any longer.
As far as my own quilting stash, I have used a lot of it for classes. If I ultimately don't like the technique I haven't spent too much money on the project. I have also used some in helping my granddaughters with their own projects. The youngest(11) just loves shopping my stash. I have also shown her how to find free patterns online. She can be a little hard to keep up with sometimes.:)
A place I have donated fabric is to the local high schools. It helps the students who can't afford to buy for their classes.