Always buy the same brand of socks. Then when finding a sock with a hole in it, do not throw away the pair. Instead save the sock without the hole and when a hole is discovered later in another pair, use the two remaining socks to make another pair.
You don't just darn the sock? I keep a needle threaded with white thread so I can mend a hole in a sock when I first notice it. When they get too worn out, they become rags for dusting and polishing.