How to get that naturally beatiful tomboy look?

I was thinking kind of like Hermione Granger or Elizabeth Swann. But Hermione is more modern and easier to use as an example. She's naturally a beautiful girl, but doesnt look all dressed up and girly all the time. Her style is cute, but she's still gorgeous when she's getting her hands dirty and battling evil. Like the naturally curly hair, natural makeup, modest clothing.