Every so often (when most of your socks are worn out), throw away all of your white sports socks and replace them with six pairs of new, identical white sports socks. Be sure to alternate the style or brand between purges so if an old sock accidentally doesn’t get purged, you can identify it when it tries to sneak back in to your drawer. All of your socks will have the same amount of wear, they all will match, and it will save you time during folding.
For your children with similar sized feet, you could buy a dozen pairs of the same sock and split them between the kids. Alternatively, you could buy each child a different brand/style/color of sock. For example, your daughter could have white socks, and your son could have white and grey socks.
Our family has subscribed to this process for many years and we love the simplicity it brings to our laundry days.