Everybody sums up the last iteration in 3 words Source:
Ask everyone to describe the last iteration with just 3 words. Give them a minute to come up with something, then go around the team. This helps people recall the last iteration so that they have some ground to start from.
What could sub-groups improve when interacting with others? Source:
Identify sub-groups within the participants that interacted during the iteration, e.g. developers/testers, clients/providers, PO/developers, etc. Give participants 3 minutes to silently write down what they think their group did that negatively impacted another group. One person should be part of one group only and write stickies for all groups they don't belong to - 1 sticky per issue.
Then in turn all participants read their stickies and give them to the corresponding group. The affected group rates it from 0 ('It was not a problem') to 5 ('It was a big problem'). Thus you get insights and shared understanding about problems and can select some of them to work on.
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.
Let team members appreciate each other and end positively Source:
Agile Retrospectives who took it from 'The Satir Model: Family Therapy and Beyond'
Start by giving a sincere appreciation of one of the participants. It can be anything they contributed: help to the team or you, a solved problem, ...Then invite others and wait for someone to work up the nerve. Close, when no one has talked for a minute.