The most destructive thing to introduce is a sense of powerlessness

The most destructive thing to introduce to a team is a sense of powerlessness; the most valuable thing to introduce to a team is a sense of possibility and control.

What I've realised is that for the situations where I have seen ineffective retrospectives, there has also been a lack in a culture of fixing all the small stuff day-by-day (aka daily kaizen culture).  My thought now is that the first step should be encouraging daily kaizen through problem / countermeasure boards, daily standups, and just continually fixing all the small stuff before worrying about retrospectives, quality circles, and the like.