City life without a car means you have to haul it yourself. This is what I do to take donations to a thrift store. I load up one of my giant IKEA bags. Carry it half a mile to the train in the morning with me. Carry it another half a mile to my school and take it to the nearby thrift store on my lunch break. It's a work out! I'm lucky I work close to a thrift store because I don't have any donation drop off points close enough to my home to walk.
Yes, I've tried calling Salvation army for a pick up, but the first time was a Saturday and I stayed home and waited for a call to come open the back door. They never called, so I called and they said not all drivers have phones but I can leave it outside on the day of a pick up. So, next time I left stuff in the alley with a big sign that it was for Salvation Army. This time they did call and I told them where it was, but only one thing of the four I left was still there. So, now I schlep it on the train one load at a time.