The authors introduce the holistic ecological approach (HEA) to talent development in sport, which proposes a shift in research attention from the individual athletes to the broader developmental context or environment in which they develop. This introduction includes ecologically inferred definitions of talent development and of the athletic talent development environment (ATDE), research guidelines and two working models. In combination these key elements serve as a guide for further research. The authors proceed to present two cases: a successful kayak environment and an ineffective golf environment, both studied from the HEA perspective. A comparison of successful environments in different sports reveals that while each environment is unique, they in many ways employ the same principles in their work. This leads to a presentation of eight common features of successful ATDEs. Moving from ecological research to ecologically informed practice, the authors add applied principles and provide an example of how these principles were used to improve the performance culture of the Danish national orienteering team. Together, the eight features, the case example, and the applied guidelines can serve as a guide for practitioners aiming to improve talent development environments in sport.