Brainstorming is a vital step in the creative process. How do you do it?
I think you have to take apart an issue. Strip it down until it's bare, then see how it can be rebuilt in a new way. Having said that, I have to say my best ideas come in the shower. (I think that's kinda funny.)
Outside the office, I walk my dog or find retail/branding inspiration. In the office, I draw diagrams on our dry erase board.
Wildly, caffeinated and on a white board with colored markers.
With (FDA approved) chemical stimulants, a greaseboard, and poor illustrations.
State the objectives
Know that any idea is worth consideration/discussion
Encourage crazy ideas
Write on whiteboards/sketchbooks
Ask more questions
Let the ideas incubate for day or two and gather as a team again to:
Bounce ideas off of client (or better yet, include them in brainstorming)
I stare at a blank screen/page until something magically appears.