Patience as well. Blueberries are gonna blueberry, and you can't expect them to follow orders perfectly or on time. And if they don't pick it up after warning them, all you do is kick them. Simple as that.
The whole "herding cats" thing becomes infinitely less stressful once you take that to heart. I can't remember the last time that someone not following orders upset me, because I just simply kick (or ban if repeat offender) from the squad and it's no longer an issue.