For me, rather than cling to the notion that these are things I need to complete and should feel guilty about not having done so, I just started accepting that they either will be completed when the time is right if they're worth my focus, or they weren't meant to be completed and there's probably something better that's come along since starting. I usually keep them all in an archive as a timeline of tinkering and a record of how much time I didn't waste on trying to complete them