Whenever you are loading the washing machine, or hanging the laundry to dry/loading the dryer, don’t put the socks straight away. If you get one sock, set it aside, and wait to have the other sock before putting them wherever they need to go. This way you drastically reduce the amount of odd socks/ socks with no pair.
If you find a single sock when you’re at the dryer, look for it in the washing or on the floor; you know it has to be there because you make the habit of always loading the pair. If you have a single sock at the washer, don’t wash it; wait until you find the other one, keep it in your basket.