Brainstorming Rules
Withholding Judgment.  Statements Are Accepted Without Comments.  Do not pass judgement on ideas until the completion of the brainstorming session.  Do not suggest that an idea will not work or that it has negative consequences.  Ideas should be put forward both as solutions and also as a basis to suggest solutions.  At this stage, devote time to the creation of ideas, and try to avoid discussing and evaluating the ideas, as this will inevitably involve either criticizing or complimenting them.

Encouragement of Ideas.  Emphasis is made on the quantity of suggestions, not quality
Brainstorming sessions should be geared towards extracting as many ideas as possible in a given period.  Keep each idea short, do not describe it in detail - just capture the essence of the idea.  Brief clarifications can be requested. 

Build on the Ideas Put Forward By Others.  Build and expand on the ideas of others.  Use other people's ideas as inspiration for your own.  Creative progress depends on good listening.  Combine several of the suggested ideas to explore new possibilities.  It is just as valuable to be able to adapt and improve other people's ideas as it is to generate the initial idea that sets off new trains of thought.

Equality Of All Participants And Ideas.  Every person has a point of view and a unique perspective on the situation and solution.  Encourage participation from everyone.  Keep in mind that some participants may feel more comfortable writing their ideas on a piece of paper and handing it to the trainer. 

It is useful to think of each idea as belonging to the group, not to the person stating it.  It is the group's responsibility and an indication of its ability to brainstorm if all participants feel able to contribute freely and confidently.  Note down all ideas.

Adapted from Rules of Brainstorming.