What makes a good leader and mentor for todays Soldiers/Sailors/Airmen/Marines?

I have been in the Navy for 8 years and have seen good leadership, bad leadership, good mentoring, and bad mentoring. The longer I stay in the more I wonder what really makes a good leader and mentor. I know everyone has their own opinions and that is exactly what I am looking for. I want to be the best leader and mentor that I can, but I realize to do that without seeking guidance would be crazy. When you say someone makes a good leader what qualities make them so? The same for mentors. Then on the other hand if someone is a bad leader or mentor what made it "seem" that way? I know perception is reality in a way. Also, what did you take from them that helps you be better? Thank you in advance.

v/r,

PO2 Roane