To begin, start with a general problem or issue which needs to be addressed. Then try to think of different issues that affect your problem, or problems that feed into it. Remember that this is a brainstorming process, which means that every idea, even the seemingly ludicrous, should be included and criticism is not allowed. The emphasis here is on getting as many ideas out as possible. Include both general ideas and nitpicky items. This all-inclusive method can lead to the discovery of problems that might not have been mentioned otherwise. Each idea should be written down (exactly as it was suggested) onto a separate card, represented by the software as a square symbol.
Once all the ideas are out, you can begin to sort them into categories of similar issues. Each category should have a heading which sums up the contents of that group. Because this is still very much a creative process, you will probably want to move cards from one group to another, and change the heading cards as need be. Many people find it works best to have the brainstorming step be done out loud, while the sorting step is done silently, with each member of the planning team rearranging the cards as he or she sees fit.