I wouldn't pair socks, personally. I would just create piles and offload pairing to each sock-wearing instance. This becomes efficient by creating piles based on intended use, and allowing each pile to have easily-distinguished differences such as color difference or size. What's interesting is that your pile criteria changes based on your socks. For me I have a long-warm pile, long-cool pile, and short pile. But if I didn't have long or short socks i'd have to create new piles: dress, casual, athletic, for example. Another pile set might be long-short-dress, long-short-casual, long-short-athletic, or long-short-warm, long-short-cool, long-short-athletic, etc.
In each case, the pile has socks that are so distinct that it becomes trivial to identify a matching pair in the pile. This is also why I don't sort by color.
In each case, the pile has socks that are so distinct that it becomes trivial to identify a matching pair in the pile. This is also why I don't sort by color.