a lightning flash is defined by the initiation and multiple development of leaders. But lightning leaders are still poorly understood. Since most of my atmospheric electricity has been focused on lightning that means that it has been devoted to understand lightning leaders. In this work, I summarize my investigations related to different aspects of lightning leaders. That includes high-speed video observations of lightning leaders, investigations of bidirectional development of leaders by means of radio mapping systems, research on the high energy emissions produced by lightning leaders and the study of upward leader initiation from wind turbines and development. In the second part, the need of an improved lightning leader model is exposed and proposed as future work. Lightning leader models can be approached by different ways depending on the purpose but agreement between all the approaches is still not complete.