I prefer stick or jump rope for flexibility and theraband for strengthening the shoulder area, specifically the rotator cuff. I feel with the therabands, it works of the muscles than loosening up the joint.
Theraband is more versatile IMO. Can use it for both stretching and strengthening. I wouldn't do the reverse stretch (going back over the top) with the stick because it's kinda shady but otherwise have at it.
One of my favorite stretches is scapular retraction. Right after you dislocate bend the arms and lower them down to your sides kind of like you're going to do some external/internal rotation. Then relax the shoulder and let the band retract your scapulae. Good stuff.