The present study analyses the use of Twitter in the course Social Media and Digital Learning, taught as part of a master's programme at Universidad Nacional de Educacion a Distancia (Spain). The main purpose of the use of this resource was to develop a learning community. This was implemented through the micro design of activities. A mixed research study was undertaken with the aim of enhancing practice and sharing the findings with the scientific community. The initial phase of the study, involving virtual ethnography, utilised observation supported by a diary to detect problems and propose solutions. Implementation was followed by a statistical analysis of the main aspects explored in the previous phase. Thirty-nine people (20 male and 19 female) participated in the study, generating a total of 3026 tweets that were subjected to analysis. The findings indicate that students actively participate in training activities using Twitter but have problems integrating interaction mechanisms. Therefore, they need to be given guidance, insisting on retweets, as well as on improving horizontal interaction. There is a tendency to send tweets via browsers and HootSuite, which avoids viewing problems. Users tend to take full advantage of the maximum length allowed by this tool. They do not perceive the character number restriction as negative and believe it encourages reflection and analysis. Training activities on Twitter follow a classic pattern, concentrated around the days in which the activities are proposed.