If, like me, you have a seemingly genetic inability to wash socks and get the same number out that went in, then I share your pain. I have had this problem my entire life.
That was until a good friend of mine taught me a lovely trick which works quite well, most of the time.
Get everyone in the house to put their socks into the laundry basket tucked into a ball together, then they will not get lost behind the washing basket or under their beds. This is a bit of a group effort, so unless everyone joins in you may still have multiple odd socks hanging about the house. But it is worth a try.