Use a handle attachment. The cable should be set all the way to the bottom of the machine.
Face away from the cable machine. Stagger your stance so you have a better base of support.
Start with a neutral grip. Flex at the elbow. While flexing twist your palm. When you hit the top of the movement your palm should be facing upward.
Guide d'Exercice Cable Twisting Curl - Entraînement Biceps | MuscleWiki