One of the reasons we hang on to things we no longer use or love is because we assume we still need them. The last time we checked in with each thing was probably when it was last used. The antidote is taking the time to individually re-consider each thing's value in our lives.
I worked with a musician client whose recording space contained his guitars and recording equipment, along with multiple stacks of boxes. He said he felt stuck in his songwriting and recording. I suggested we take a look at what was in the boxes. My client made a grimace face along with a groan. He said, "Do we have to?" I said, "Now we especially have to."
The majority of the stuff in the boxes were music books and magazines. They contained stories of songwriters, musicians, and recording engineers that inspired him at the time of reading. I asked if he ever re-read them. It was hard for him to say no because he was feeling attached to the memory of the good feelings he got from the reading. But he hadn't re-read them; it was his nature to not read them again.
My client looked at each magazine and book and reconsidered his needs based on what would serve him now. At one point he got stuck and said, "I can't get rid of this, it's a great article about Neil Young." I had him open up the magazine and start to read the article. He only made it through a few sentences before he put it in the giveaway box. Once he got it that he wasn't actually interested in re-reading the bulk of the stuff, the process went quickly and pretty much all the items went into the giveaway box.
We moved the boxes out to his truck and brought them to a Goodwill. They were happy to take them. We came back to my client's place and I asked him to play one of his guitars. He played with great passion. He said he hadn't felt that free with his music in a long time.