There are many different ways to brainstorm.
Your could create a
Mindmapeither by hand or using software.
You could create a Moodboard.
Ether way...its all about creating ideas!

mindmapping1.jpg
This is a mindmap about mindmaps!
evaluation-process.jpg
This is a Minamap about evaluating Technology projects

example_mood_board1.gif
MoodBoard for interior design

mb12.png