What creative solutions have you found when trying to include and represent everyone's voice in a group decision?

You can usually get good ideas from a wide multitude of people, but the issues begin to arise the longer the group is established. In the beginning we inheriting try to find what we have in common, and tackle those issues with precision that makes everyone happy. But the longer the group is established, the more we begin to see our differences. Which leads to nothing more than strife and confusion amongst people watching from the outside.