envy my US family members. When they have a bunch of crap they want to get rid of but not throw away, they can just put up ads, throw up a table outside, put the things they want to get rid of on the tables, and people will come buy or take it. All in one job. Anything left over can be donated to a place like Goodwill or the Salvation Army, who will take even decorations. Anything they reject isn't much and can be tossed with minimal guilt.
I want so, so desperately to get rid of my things via yard/garage sale. But, that's not something you do here. As for donating things...they take clothes and shoes. The rest, you seem to be on your own. I've asked around, and it seems the only ways to get rid of things are a little tedious. List them all on eBay or Amazon and spend your days making tiny appointments for pickup of small crap or buying and wrapping and mailing zillions of packages off. It's so labor-intensive compared to just plopping it all on the sidewalk or dropping it all off in one place.
If it does come down to wasting it all in the trash, that's not so simple either, of course. You can't just put it all on the curb on trash day. Toxic or large trash requires pickup by appointment or delivery to the junkyard by car.
I'm still researching options that aren't so nitty gritty, so one-item-at-a-time, so much Deutsch speaking and appointment making and Post using. Wish me luck. Because all the way in the back of my mind is going to be that easy, easy garage sale that I cannot hold, and that Goodwill that would have taken my unneeded headphones and pillows. I think moving out of Germany is going to be a lot harder than moving in!