I know many of you probably donate your old clothes to places like Good Will. And that is great - it is a great organization - they provide jobs and other programs and someone else who is plus sized gets the benefit of cheap gently used clothing. I totally support that!
I just thought I'd suggest another option - seeing if a local shelter or psychiatric hospital could use clothing donations.
I used to work in a psychiatric hospital in New York City and there was a great need for women's plus size clothing. A lot of medicine for schizophrenia and other related disorders tend to make people gain weight. As a result of the meds combined with poor nutrition, there are a lot of plus size people in the psychiatric hospitals and shelter systems of New York. I would guess that is the case universally. And many of them don't have adequate or properly fitting clothes. Bras were another huge issue I noticed - I often saw women inappropriately small bras or no bra at all in the psychiatric wards simply because they couldn't find large enough bras in the donation piles (the patients usually came in from the streets - so they had little or none of their own clothes). At one time, I actually had a women come up to me and ask if I had any old bras she could have (I did and I brought them to her). So consider looking into seeing if local shelters or hospitals may need your clothes! You really could directly enhance the quality of someone's life!