Gear: Sell some online, keep some decent stuff as loaner gear, and donate the heavy items to youth or wilderness firefighters (Durango CO had gear collection points during the huge fires 2001 or2). Some gear can be repurposed. Threadbare hiking shirts are great for hot-weather mountain-biking too.
Other stuff: I digitize music, videos, + books, so most physical copies were sold to a used bookstore. Can't really digitize a frying pan or furniture for cooking an entertaining, tho; other hobbies can be space hogs (think about a music playing family storing pianos, upright basses, and a "drum set") but look at your activities = requirements (space, maintenance, etc..) - discard excess (reuse, donate, recycle, and toss as a last resort). Edit: some stuff is good, especially if the 1 tech item can replace bigger, bulkier one(s).