Lingerie Bags I know - it sounds weird but they really do work.
Here is how it goes: each family member gets a lingerie bag and it is marked with their name in laundry marker. Every time socks leave their feet - they go into the lingerie bag. On laundry day the entire bag is placed in the washer and then the dryer (it usually works best this way) and then the socks are sorted and relegated to their home.
Loc-a-Soc. This is a product where you, well, lock your socks. They come in a 10 pack and in various colors. Each family member would get a specific color. Not a bad idea - I just don't see children and husbands locking their socks.
Moving on - what do you do with that one sock? Facing reality is often the toughest thing you will have to do. However, accept the fact that the other half of that pair of socks is never returning and get on with your life.