After reading The Life Changing Magic of Tidying Up by Marie Kondo — a book about how to tidy up by discarding items that don't "spark joy" — I adopted a simple strategy: when I buy something new, I get rid of something old.
Anytime I buy something new, I will get rid of (via donation) a similar item. For example, if I buy a new jacket, I will give away an old jacket. It's essentially an upgrade system, but it encourages a minimal approach where you only have 1-2 items per category.
I've become increasingly tired of "stuff." I used to love buying new clothes, but now I absolutely hate it. I want a curated set of quality items I actually wear and enjoy. Everything else is a waste of money and space.
I like this system, and I've adopted it for everything, even technology. It helps me focus on the items that spark joy for me, and rid myself of unnecessary items that someone else could use.