What are your brainstorming techniques?

When Your in any type of game jam, most the time you need to brainstorm. Not just be able to brainstorm but do it quickly. So how do you guys brain storm quickly for game jams and just normal projects. I like to list a bunch of random words or mechanics and then write down how the game would play out like this:


Turtles
This would be so boring

Platformer
Move around
Jumping
Power ups

Zombies
Be exactly like any other zombie game for that amazing cliche feeling


So how do you guys do it?