Retrospectives can have different purposes. A suggestion how you can classify retrospectives and pick appropriate exercises to make them more valuable for their teams.
A retrospectives of retrospectives helps to improve collaboration between teams, increase their contributions in the project and to share learnings across projects.
Retrospectives exercises for teams which have more than one customer, maybe even multiple product owners.
The most important thing is never to forget to appreciate and thank your team members for the ways they have helped each other.
This is the story of how a reader of our book on Valuable Agile Retrospectives dealt with negative issues in his retrospective.
The dispersed team questions retrospective exercise is a variant of the questions-based retrospective for teams consisting of members working from different locations, for example team members working from home or working in different offices, countries or even continents.