What are the proper form and technique for performing rear delt flys with cable?

To perform rear delt flys with a cable machine, stand facing the machine with your feet shoulder-width apart. Grasp the handles with an overhand grip, keeping your arms straight. Engage your core and squeeze your shoulder blades together as you pull the handles out to the sides, keeping a slight bend in your elbows. Slowly return to the starting position and repeat for the desired number of reps. Focus on maintaining proper form and control throughout the exercise.