When it comes to Brainstorming fear is a major obstacle. Facilitators need to design brainstorming exercises so that fear is mitigated in individual participants - this is often accomplished by adding anonymity to the exercise - if groupware is available then groupware should be used - if a low tech approach is required then initial rounds of brainstorming can be done with participants individually brainstorming and then having a moderator capture all the ideas on charts or boards for future rounds and elaboration.