Ooh this is a tuff one.
Let's see:
1) "I kick ass!" I tell myself this quite often. It makes me feel like I can do whatever I want. Arrogant? A bit, but it sure beats when I used to think, "I'm a bid loser."
2) "I don't care what other people think about me." This is an important one. I define myself from with in, not from what other's say. I use what positive things people say about me, but most of my confidence comes from inside.
3) "God loves me." Ok, so my religion is helpful in my confidence, so sue me. God created me and loves me. So, what else is important? I love me, ok that too. Anything else? No. God and I am my biggest supporters. If you have that, you need nothing else.
Anyway, those are the sources of my power.