My kids are very much given a lot of opportunity to be themselves and all of them are very unique and all have very good self-esteem but they are also taught to be kind, not a show off, be happy for others, not lie or cheat, respect others adults or children. Basically, respect others and yourself. They hear and see it at home, at church, and at their Christian school. It is reinforced immediately when they are not. They have to apologize to the other person, looking them in the eyes and say what they are sorry for. We also have another policy. The other person is not allowed to say "It's okay." They say "You are forgiven" Then we encourage them to move forward and forget about it.
When we play, I am with Dude, cheating and whining means an immediate end to the activity. There is no discussion about it unless on their own, they apologize. Crying and meltdown-- if that's your emotions fine, but have it in your room, the rest of us don't want to hear it. You can come out when you have yourself under control.
You have to model it and reinforce it. Our kids call us out sometimes and we will apologize to them if we have to.
Honestly, I have two gifted kids and I tell them "It doesn't matter how smart you are, it's what you do with it. Do you do good things with your brain?" I also tell them "Integrity is the most important thing you can have, it is far more important than being smart"
