I shoot with someone who has chronic shoulder pain, and he was told that drawing the bow with a low elbow, so that the elbow never rises above the position it assumes at full draw is better for the shoulder than drawing with a high elbow so that the elbow comes down to its position at full draw. I don't have shoulder problems (yet) but I've tried drawing both ways, and the low elbow approach does feel better to me.
Clearly, though, the obvious and most important thing to do is to shoot as low a poundage bow as will fill your needs. Unless, of course, you just make up for shooting a lower poundage bow by shooting more arrows!