Collect some news headlines in advance and take them to the retrospective to serve as examples. Try to gather a mixture of headlines: factual, opinion, review. Place the headlines where everyone can see them. Hand out sticky notes. Give team members 10 minutes to come up with their own headlines describing newsworthy aspects of the sprint. Encourage short, punchy headlines. Stick the completed headlines to a whiteboard. If any cover the same news item, combine them. If any are unclear, ask the reporter for details. Vote on which news items to discuss and analyse in more depth.
Hand out pens and sticky notes. Ask everyone for ideas on how to turn the next iteration / release into a certain desaster - one idea per note. When everyone's finished writing, hang up all stickies and walk through them. Identify and discuss themes. In the next phase turn these negative actions into their opposite.
If your team has a tendency to see obstacles outside of their team and influence and primarily wants others to change, you can try this activity:
Draw a big rectangle on the board and another rectangle inside of it, like a picture frame. Hang all complaints and grievances that surfaced in previous phases into the frame.
Now comes the interesting twist: Explain that if they want anything in the outside frame to change, they will have to do something themselves to affect that change. Ask the team to come up with actions they can do. Put these actions into the inner rectangle (near the outer sticky they are addressing).
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.