Before starting a new thread I searched here and found this one from 2011.
Seems two or three categories.
1) How to repair a good sock that is only worn out at the heel.
2) how to repurpose the sock for outdoor use
3) how to repurpose the sock for home maintenance, garage tools, non outdoors BPL use.
For me in coastal sunny Southern California, might get a total of 30 days at most that are worthy of long sleeves, still it could get freezing cold *insert comedy* when the morning temp dips to 50F before I go to work. So I demote my smart wool socks to office socks during that ice age for us wimpy SoCal lowland dwellers.
I was really hoping for a cheap and bandaid fast solution to get the worn out smart wool socks back into hiking condition. I don't want to sew with the plastic egg.
The socks I got on sale for under $10 so not worth spending $5 plus time, when the easier solution is buy buy buy... Sadly.
I do like the idea of cutting a thumb hole and convert into mittens, though I have 7 pairs of a variety of gloves in the closet waiting for global warming to end, so I can welcome the next ice age.