If your boss had witnessed the last iteration, what would she want you to change? Source:
Imagine your boss had spent the last iteration - unrecognized - among you. What would she think about your interactions and results? What would she want you to change? This setting encourages the team to see themselves from a different angle.
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.