In my previous work I used to come across youth (& adults) who where just starting out so would donate my old gear to get them started.
I've left open face etc in foreign climes rather than bring them back as part of my luggage allowance (locals like brand names)
I gave the 2 I bought for MM in Malta to charity shop (Not sure if they sell or not)
I've seen the hanging basket idea (old shit in the garden doesn't appeal (but don't mind at the allotment
So other than landfill (after my last clear out I filled a council bin) what's your solution (if any)