Well, I'm not afraid of looking into the mirror...
To keep up my self confidence I usually try to remind myself all these powerful and thought provoking song lyrics that inspire me to act confidently. Sometimes it works, sometimes it doesn't. I think it all depends on situation. The important thing is also not to try to compare myself to other people. It's hard to bypass this thing in everyday life but it might bring a lot of joy when you realize that no one is better than you, he/she is just different...not better, not worse just different. So another question is: "What can you do to stop comparing yourself to other people?"