Six perspectives, one at a time. De Bono's technique splits thinking into six 'hats' so that emotion, data, criticism and creativity don't collide in the same conversation.
Each hat is a mode of thinking: white (data), red (emotion and intuition), black (risks), yellow (benefits), green (ideas) and blue (process). The key is that the whole group wears the same hat at the same time, instead of arguing from six mixed angles.
I use it to unblock meetings that get tangled: forcing the black hat's turn surfaces the risks without it feeling like an attack, and the green hat opens up ideas without criticism killing them too soon. It structures the conversation without making it rigid.