Brainstorming is a social event but the best ideas come from the solitary thinking before meeting up with the group.
Team brainstorms can easily be dictated by the person that merely talks the most which often leads to groupthink. People are willing to support any idea that requires them to think no further. But you can keep the team responsible and open-minded with just a few ideas of your own.
Brainstorms are really about combining a plurality of ideas and then playing a little devil’s advocate to make the group justify their idea. The brainstorm is just as much an ideation session as it is an open debate. But if there aren’t any ideas to begin with, they’ll be nothing to talk about. So come prepared by bringing your own first.