The trick with hot girls is to talk to them exactly like you would any other. Don't let yourself think that she is hot otherwise, you will simply become intimidated, tongue-tied and not your natural self.
Good ideas may be giving her compliments, asking her questions about herself and her interests, and generally conveying your care for her. Women respond to men who support them, respect them, and adore them.
You should find something to tell her other than that she is "hot." While women generally appreciate it when their dates like their bodies, they want a bit more. You should be sure to find traits that you like in her other than her looks and tell her about them.
Just make sure you don't tell the same thing as she's heard from 20 other guy's every day be fun and different if she really hot she got options. Be confident and have fun and let her know you like for her to personality