My feet still get cold on the descent even with touring socks. What am I doing wrong?

The most common cause is still overheating on the climb. If your feet are sweating heavily on the ascent, no sock can keep them warm on the descent — the moisture will cool rapidly. Try these fixes: (1) Use a lighter-weight sock or one with more ventilation. (2) Open your boot buckles slightly on the climb to improve airflow. (3) Remove your boot liners at the top to let them dry during transitions. (4) Make sure your boots aren't too tight, which restricts circulation. (5) Consider adding a vapor barrier liner sock for the descent on very cold days. The solution is almost always better moisture management on the climb, not more insulation.