In this work, we consider learning analytics for primary and secondary schools from the perspective of the designer of a learning system. We provide an overview of practically useful analytics techniques with descriptions of their applications and specific illustrations. We highlight data biases and caveats that complicate the analysis and its interpretation. Although we intentionally focus on techniques for internal use by designers, many of these techniques may inspire the development of dashboards for teachers or students. We also identify the consequences and challenges for research.