A routine that I heard of a while a ago, but my first opportunity to employ it. In advisory we were looking at stress. As a warm up we did the Four Courners discussion routine.
Each person got a post it note where they could write their own reflection or response to the topic. Then in their table groups they shared and listed out patterns or key information.
An example of one from the Grade 8's is here:
I like this because everyone has a day, enables the quiter ones to have a voice, can get a snapshot of all views in the class, forces everyone to be involved and you can then post then around the room or refer to them at another date.