Using a rope or bar handle attached to a cable that's set above your head, do a set with an upright torso while standing about 4-5 feet back from the cable column (8-15 reps).
Then do a set with your torso parallel to the floor.
The point of maximal mechanical tension is when your arms form a 90-degree angle to the cable. So, upright torso pulldowns focus more on training you in the shortened to mid-range aspects of shoulder extension. Performing them with your torso parallel to the floor focuses more on the lengthened to mid-range.
The true Master Blaster pontificates on shoulder training, adding muscle without putting on fat, BCAA's, whole eggs vs. egg whites, hot Asian chicks, recruiting more motor units, dumb exercises, bar speed, and his inability to love. (We made up that last one.)