I have been taking tips from a friend of mine - if you don't want or need it, put it in a box, priced already for a yard sale... then have a yard sale once or twice a year and what doesn't sell, try one more yard sale then after that, out the door it goes to GoodWill. I still donate a ton of stuff but I also get an added benefit of getting a little money to get something else that I might need or to go out to dinner.
I also sold a ton of fabric on Craigslist recently.
I am organizing and supplying all the fabric for a children's charity quilt sewing day in October so a lot of what I have will be used that way (if all goes right!)