How do you ask out a girl who's out of your league?

There's this woman I've been seeing around alot and she's gorgeous and I'm well above average so I figure I got nothing to lose. I know you don't compliment a beautiful woman on her looks cause she knows how good she looks and gets told all the tine buy guys that are much better looking than me so I'm not gonna score any points for that so how would I go about it and what are some things I should focus on