How to Avoid Groupthink? Six Thinking Hats
Edward De Bono's Six Thinking Hats
method is an excellent way to avoid Groupthink. In this approach everyone together play different roles: devil's advocate (black hat), idea creator (green hat), new information provider (white hat), discussion leader (blue hat) and so on.
Because everybody switches the perspective towards some issue together, having a deviating opinion in the group is not scary, but on the contrary it is welcomed and is what the group is actively looking for and supporting.