The purpose of this Theory to Practice article is to present a systematic, cross-disciplinary, and accessible synthesis of relevant research and to offer explicit evidence-based design guidelines to help practitioners design better participation processes. From the research literature, the authors glean suggestions for iteratively creating, managing, and evaluating public participation activities. The article takes an evidence-based and design science approach, suggesting that effective public participation processes are grounded in analyzing the context closely, identifying the purposes of the participation effort, and iteratively designing and redesigning the process accordingly.