I don’t know that there is any specific guidance on how to appear to have cut ties. When I was trying to distance myself from someone, I didn’t want to keep defining myself in relation to them, even in terms of not being tied to them.

I see a time like this as a chance to learn more about yourself. Explore with different ways of self-expression within your means, see what fits, and take it as far as feels right. Gumtree or Craig’s list are good places to start, see what calls out to you and feel free to repaint, redecorate, or modify as needed. Paint is cheap, so playing with new colours and patterns is a good place to start. Just make sure that whatever you choose expresses something real about you, not how disconnected you are from someone that isn’t relevant to your life anymore.

Have some shelves made out of like 2-bys and cinder blocks, that’ll make you look like a drifter for sure

Empty apartment with a mattress in the floor. Photo frames face down.

Who is going to see the space?

Bubble wrap

Whatever you can find used.