My parents divorced long ago. They have taken somewhat different routes with our and their stuff.
I have a sister, and while we don't agree on everything, this is an area where we have co-operated well.
Mum + husband have a total of six kids from previous marriages, lives in a house that is slightly big for them, but nice when we visit. Their decided that they don't want anything in the attic and other storage areas except for Christmas decorations, so "kids, you are grown up, come get your stuff, you have two years from now bc that is when we retire and then we want this completed". We all came, sorted and tossed, together with them as they also went though theirs. Lots of nice everyday stuff in good condition from grandparents etc to charity. They have kept certain smaller items, which they display (Mum: if I want to keep it, I want to display it). Mum has put notes under some inherited things, so we know if is from her side or her husbands. They do have quite a lot of stuff, but if we ever need to sort out their house, it will be quite easy.
Dad is different. He is somewhat of a hoarder. Nice things like decorative glass, paintings etc, but still. Way too much, it would look a lot nicer with less. Sis and I were asked (in a nice way) to pick up our things from in-house storage as he"needed more space". We went through together, had fun and tossed most. Dad was looking at what we tossed, commenting "but you shoould keep that..." - lots was crap from school. So sis and I agreed that we needed to dispose of everything ourselves bc "if we leave in the bin, he may want to go through and pick out things..."
After, dad commented that even though we took our things, it didn't make much if a difference. Well, no surprise as most stuff in storage was his anyway.....
Sis and I say to each other now and then that this house will be tough to take care of... but it is not a lot that we want to keep so that makes it easier. It's mostly things he bought, no family history and not our style.
Anyhow, it feels really great to know that I don't have a lot of stuff that is mine at either place. I have all my belongings where I live now, had a storage unit for a couple of months during moving/showing the house, but emptied that when I moved. I still have some items in my own storage to go through but it's getting better by the day. Currently going through papers, it is tough, but it's already better.