One of the most rewarding experiences I had was when I lived with a dear friend whose surroundings were chaos. Mountains of everything, everywhere. When I asked if he wanted to move into my house, he warned me he was messy. Of course I already knew this and said I wouldn't judge his messiness if he didn't judge my tidiness. So I made a suggestion that might work. I kept the bathroom and kitchen clean then I gave him the dining room as his space and kept the lounge as mine. He thought that might work and moved in.
It didn't take long for me to realise that he knew where every single thing was in his piles. I would need a copy of a bill and he would magically go to the exact place in the pile and pull it out. This taught me the sensitivity and respect to other people’s sense of order that I've mentioned elsewhere.
When his stuff started arriving and staying in my lounge, I let him in on one of my tricks. The Dump Spot. I asked him to allocate a space in the dining room where I could put whatever needed to be relocated back to him and he chose a corner of the table.
I never had any reason to go into the dining room because I ate in the lounge on my knee and he enjoyed joining me occasionally in the peace and warmth of the lounge so this set up worked perfectly and we never once had an issue in the almost two years we lived together.