A growing body of evidence indicates that, increasingly, the public is engaging with science in a wide range of informal environments, which can be any setting outside of school such as community-based programs, festivals, libraries, or home. Yet undergraduate and graduate schools often don't prepare scientists for public communication. This practical guide is intended for any chemist--that is, any professional who works in chemistry-related activities, whether research, manufacturing or policy--who wishes to improve their informal communications with the public. At the heart of this guide is a framework, which was presented in the report "Effective Chemistry Communication in Informal Environments" and is based on the best available empirical evidence from the research literature on informal learning, science communication, and chemistry education. The framework consists of five elements which can be applied broadly to any science communication event in an informal setting.