We are also in the process of downsizing, and it's hard work. Clothes I have no problems with - I've been retired for 5 years, and haven't worn most of my 'work' clothes since I retired. Everything we do is more casual. Even weddings just require black dress pants and a dressier top, which I have.
I'm struggling with the things I do use, but just occasionally. The Christmas platters that have been used for cookies for years. Sure, I could just use a dinner plate, but those platters seem to be an important part of Christmas, even more important than the tree.
I don't have a big stash, so I'm keeping it. Most of my quilting/sewing is for charity, and my stash works fine. It's become a challenge I enjoy - to make something great from what I have on hand.