Be rational

Remove wasted emotions like guilt and insecurities. It's a lot easier then it sounds. Insecurities are NOT things that you are not aware of, they are just issues you do not want to deal with. Two quick examples:

1) I lost two fingers when I was 3 - I have never been insecure AT ALL (thanks I am sure to my family) - but why? Because I am missing two fingers. No you did not miss anything - it's teh reality. There is nothing I can do. There is no game, there is no reason for me to hide from it - it is what it is, so qhy cry about it.
2) I had thin hair - in HS it bothered me, so I attacked it, shaved it all off - no more insecurity.

Have you ever noticed that you can almost always give someone else better advice then you can give yourself? Why is that? Because when you are trying to think through your own brain - you are typically dealing with your heart as well. This is very ineffective. When you want to understand yourself, you need to be cold and almost distant - especially when it comes to doubt/ego.