One day I decided that I was beautiful, and so I carried out my life as if I was a beautiful girl.
Close your eyes and imagine the best version of you possible. That's who you really are, let go of any part of you that doesn't believe it.
There's nothing interesting about looking perfect - you lose the point. You want what you're wearing to say something about you, about who you are.
You really are good enough, pretty enough, and strong enough.
Just be yourself. Let people see the real, imperfect, quirky, weird, beautiful and magical person that you are.