When we started the process of tackling this sock drawer, it was filled up to the brim with a zillion socks. Because of how they were folded, and because of how many there were, we had no idea what he had. So we emptied the entire drawer and he kept only the socks that were worn on a regular basis, as well as the ones that he loved. We then color-coded them as best we could and then folded them.
To fold them, we laid one sock on top of the other then folded the bottom part up 1/3 of the way, then we took the top part of the sock and folded it down 1/3 of the way. Now you don’t see all of the strings that are on the inside of the sock and he knows exactly what pair it is when he pulls it out of the drawer. We used the KUGGIS bins from Ikea to categorize the socks according to color or type.