This document provides tips for communicating Citizen Science projects and using social media engagement. It recommends targeting key audiences and engaging citizens early in the design process. Planning social media content should make the project aims and calls to action clear, and explain why citizens should participate and how their contributions will be used. Popular social media channels like Facebook, Twitter, YouTube and Google+ should be used consistently to support engagement with project communities over the long term. Images, video, guest posts, and live events can help build trust and encourage participation and sharing.