Place a circle or sphere in the middle of a free space. Let the team gather around it. Explain that the circle is the center of approval: If they agree to a statement they should move towards it, if they don't, they should move as far outwards as their degree of disagreement. Now read out statements, e.g.
I feel I can talk openly in this retrospective
I am satisfied with the last iteration
I am happy with the quality of our code
I think our continuous integration process is mature
Watch the constellations unfold. Afterwards ask which constellations were surprising. This can also be a closing activity (#53).
Explain an example of Value Stream Mapping. (If you're unfamiliar with it, check out this video or this printable 1-pager.) Ask the team to draw a value stream map of their process from the point of view of a single user story. If necessary, ask them to break into small groups, and facilitate the process if they need it. Look at the finished map. Where are long delays, choke points and bottlenecks?
Prepare a flip chart with 3 columns titled 'What', 'Who', and 'Due'. Ask one participant after the other, what they want to do to advance the team. Write down the task, agree on a 'done by'-date and let them sign their name. If someone suggests an action for the whole team, the proposer needs to get buy-in (and signatures) from the others.
Divide a flip chart in 3 sections titled 'More of', 'Same of', and 'Less of'. Ask participants to nudge your behaviour into the right direction: Write stickies with what you should do more, less and what is exactly right. Read out and briefly discuss the stickies section-wise.