Mobile and social media over the last decade has created significant shifts in society: how we communicate and collaborate, and in learning and teaching. This paper discusses a study that investigated how mobile social media tools and affordances could be harnessed to facilitate a student-determined learning experience (heutagogy). A design-based research (DBR) approach was utilised to analyse and investigate a set of draft design principles that was established in collaboration with a group of teachers and literature. The draft design principles guided the design of a first year course that was iteratively implemented and evaluated over 2 years with two different cohorts of students. As a key outcome of the DBR, a set of refined design principles is presented. These principles are capable of guiding other practitioners in designing and facilitating student-determined learning in authentic contexts using mobile devices, and social media affordances.