Using games for education can increase the motivation and engagement of students and provide a more authentic learning environment where students can learn, test and apply new knowledge. However, the actual (serious) game application in schools is still limited, partly because teachers consider their use as a complex process. To increase game adoption, the integration of Game Learning Analytics (GLA) can provide teachers a thorough insight into the knowledge acquired by their students and usually presented through a visual dashboard. Although it is possible to provide a useful general metrics and a prefab dashboard, it may not fully cover teachers' expectations. In this paper, we study the ad-hoc adaptation of generic dashboards to increase their effectiveness through three case-studies. In these experiences, we adapt dashboards for teachers to include detailed information for more-focused analysis. With the positive results obtained from these scenarios, we have identified a methodological process to create ad-hoc GLA dashboards and extracted some lessons learned for dashboard development: simple but useful dashboards can provide a higher added value for stakeholders compared with more complex dashboards; teachers and game developers should be involved in dashboard design for better results; and, if possible, ad-hoc developed dashboards should be used as they have proved to be more effective than generic dashboards.