Latest since the publications by Daniel Goleman on Emotional Intelligence you should know that Self-Control (more precisely: self-regulation) is essential for you if you want to be a great leader.

The article below "Leadership Takes Self-Control. Here’s What We Know About It" suggests three keys to boost self-control in organizations:

"Ultimately, the keys to avoiding self-control failures are to 1) allow the body to rest and restore self-control, 2) reexamine existing organizational policies that might inadvertently reduce employees’ self-control, and 3) create a culture that deters negative behaviors in moments of reduced self-control."

Interestingly, once again sleep and rest turn out to be essential elements for better self-control and better leadership.