To get the most out of the face-pull, don't treat it as a progressive-overload exercise. Keep 'em light. Do 3-4 sets of 12-20 reps.
The beauty of the face-pull is its versatility. It can be done with an overhand, underhand, or neutral grip, and you can also vary the height of the pull (low cable pulley shown here). They all work, and it's wise to rotate them every few weeks to bulletproof your shoulders from all angles.
Whether or not your shoulders are banged up right now, make this a staple from now on. You'll thank me later.