Put up two posters labeled 'proud' and 'sorry'. Team members write down one instance per sticky note. When the time is up have everyone read out their note and post it to the appropriate poster. Start a short conversation e.g. by asking:
Did anything surprise you?
What patterns do you see? What do they mean for you as a team?
'Imagine you could time travel to the end of the next iteration (or release). You learn that it was the best, most productive iteration yet! How do your future selves describe it? What do you see and hear?' Give the team a little time to imagine this state and jot down some keywords to aid their memory. Then let everyone describe their vision of a perfect iteration. Follow up with 'What changes did we implement that resulted in such a productive and satisfying future?'Write down the answers on index cards to use in the next phase.
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.