In early retrospectives, expect to go first, admitting a mistake of your own. You can also “seed” the retrospective by keeping an ear to the ground for good items for reflection, and say things like, “You folks really figured it out. I hope you’ll mention it Friday at retro so others can learn from it.” Or “You really struggled with that. Would you mind bringing it up Friday so we can figure out how it doesn’t happen again?” But nothing beats being willing to go first.

