Feel good in your skin. Be comfortable with who you are, love yourself. I believe that as soon as you feel good, see how you unique you are, and discover the magic of the human body, the universe responds and gives you something back. I started to practice this and putting any shyness aside, but something very important is to have a balance, so it has nothing to do with arrogance is about being humble, leave your EGO where it belongs, and be grateful.
You don't need to be the prettiest, you just need to believe that you are the best that you can be with what the universe has giving you, and everyone will get that picture, as simple as that. They will see you glow on your own.
Some people are really good looking but if they don't know how to practice these skills nobody will notice them. Sometimes every guy on a club wants dance with one particular girl, she is not the prettiest but she has something that prettiest girls wish they had.
This is the best picture, in my opinion, of the one and only Marilyn Monroe. She was gorgeous but is more than that, she was confident, she knew the power she had and she worked it.