I don't often do a big cleaning, but I routinely get rid of stuff that I don't wear or use. I keep a "charity basket" in my spare bedroom and put things in there as I find them. It's a lot easier that way and I don't get tired or sorting and just dump stuff and then wish I hadn't.
I dont' really use any "method" for doing this. With me, if I don't see a use for it and it's not a special collectible item, I get rid of it.