Outside of mentorship and practicing your leadership skills, how do you primarily better educate yourself on leadership skills?

I'm a millennial so I watch speeches and seminars on YouTube. Everyone from General Patraeus to Mark Cuban have gotten a view from me. If anyone has the time, I highly recommend CW4 Micheal Durant's 1 hour speech about the events of Black Hawk Down. Great thoughts on organizational leadership and communication.

The scope of leadership book series is a great start.

I think "all of the above". I watch the greats in my Command, of which there are innumerable both Active and Retired. I read books on the subject and glean from that. I watch videos. That's the beauty of modern technology--if you seek it, you can find it at your disposal! :) Not all advice or guidance is gold, but you learn to sift away the shyte

A lot can be said about reading up on the subject. But it will only get you so far. Additionally, observing other leaders can provide great insight, but it can seem impossible to emulate if you don't understand what a leadership mentality is. I think reading about leadership and then observing leaders would provide the opportunity to not only see what you have read be applied but also to give the insight you need to understand why leaders react the way they do in different circumstances.

Get all the service school 's you can get, do your job well and don't give your leader's any
problem's

I pay attention to what's going on in group settings, but I also like to complete online training once in a while. If I come across readings or videos, I'll check them out, too.

https://www.youtube.com/watch?v=7bB_fVDlvhc

I've shared this previously, but the "Law of 33%" is great. The relationships you develop will affect you greatly. If you dedicate 1/3 to people you would like to emulate (people you would like to have as mentors), 1/3 to peer groups, and 1/3 to "juniors" (people you can mentor) it can help.

I think its best to find some one you would like to emulate - this takes a lot of time in understanding your strengths and weaknesses. However I'm a firm believer in that if you have your act together people will seek you out or seek out your leadership. Name a leader all ate up?

I read a great deal and study people.