That phrase "you check the strip first, every wall" is the whole thing right there and I'd take it even further. Before anybody touches a stretcher, walk the room and put your hand on every inch of tack strip, if it lifts up even a little it gets another nail or a new strip period. Same goes for the pad, make sure it's stapled and trimmed right, cause a loose strip or a bunched pad will wreck your stretch no matter how good you are on the pole. Then when you do stretch, work in small bites and check the strip behind you as you go instead of yanking the whole wall at once. On training new guys, don't make it a lecture, just make them do the walk with you and point at the loose spots so they see it themselves. Show them what happens when you skip it, one pull and the strip pops, and they won't forget it. It's not being a jerk, it's called having a system, and the guys who last are the ones who learn the order and stick to it.