I've also found brainstorming isn't great for more "creative" thinkers. In a group setting it's easy to say "no that won't work" or not get buy-in on the spot, so ideas that aren't mainstream get shot down right away.
People like me also need time and space to think deeply about certain topics, and a brainstorming session has neither time nor space, so you're immediately limited in the ideas that are presented.
Those people aren't brainstorming; the rules should be that ideas get evaluated later, and that no idea is too outlandish, even if it "won't work". You write every idea down, and cull later, at which point people have had time to think about how something might get done, rather than simply to cancel it off the cuff.
+1. Brainstorming is a way to generate leads by leveraging diverse group of minds/experiences/skills. In a healthy environment, such experience may be even bonding for the team, as long as ranks and seniority are left at the door (which is not easy).
Just clearly write out the scope and purpose, timebox it, and collect/record the ideas, no judgement, not even attribution. Then the next time, see if anything converges, evaluate what can be done.
“as long as ranks and seniority are left at the door.”
100%. We had anyone who wanted to join, and nobody’s ideas were better than others. One of our most beloved features was one that our EA came up with in such a session, because she didn’t have the context to think it was hard to do. A few days later, we found an easier way to do it, but we’d never even have looked if it weren’t for the humility and collaboration in that room that day.
People like me also need time and space to think deeply about certain topics, and a brainstorming session has neither time nor space, so you're immediately limited in the ideas that are presented.