At-home washing: Use regular detergent (no bleach!) on the normal cycle, and turn inside out to remove dead skin and sweat buildup where it counts. Add a liquid fabric softener during the wash cycle, but use it sparingly! Too much can result in a slick, oily feeling, but just the right amount will keep your socks soft and cozy. Dry socks thoroughly on a normal setting. Don't put them away damp; it can lead to the breakdown of the elastic.
In the field: After a few days of use, padding inevitably gets compressed with dirt and sweat. At rest breaks remove your socks, flip them inside out, and rough up the fibers with your fingers. Shake loose any debris. For the most part, the best way to dry wet socks is to wear them, as unpleasant as this may seem. If friction blisters threaten or if your feet produce too much sweat to let drying happen, change into a fresh pair, then tuck the wet ones under your shirt where your body heat will dry them. If it's hot and sunny, strap the wet socks onto the outside of your pack to air dry.