Social awareness applications are based on the idea of a group sharing real-time context information via personal and ubiquitous terminals. Studies of such applications have shown that users are not only concerned with the preservation privacy through non-disclosure. Instead, disclosure is manipulated for the constant presentation of self to the group in everyday social situations. Basing on 3 years of research with the mobile social awareness system ContextContacts, established findings in social psychology and ubiquitous computing, we propose a number of design principles to support users in this management of privacy and presentation. These principles are to apply even if disclosure is automated, and include support for lightweight permissions, assuming reciprocity, appearing differently to different audiences, providing for feedback on presentation and allowing lying. These principles are applied in interaction design and protocol engineering for the next version of a mobile awaren...