Some things that some women love to hear are, "Your personality is one of my favorite things about you," and asking her to talk more about something for which she has passion. Other things that a woman may love to hear are reminders that she is cherished and that she makes her partner proud.
More examples of what a woman may love to hear are that her insecurities are some of her partner's favorite things and that there are many little things about her that her partner loves.
Asking a woman to talk more about her passion shows that person is showing interest and taking her passion as seriously as she does. Complimenting her personality indicates that her looks are not the only attractive thing about her.
A partner telling a woman about the little things that are lovable can include a cute laugh. It may even include personal quirks like the way she bites her nails when she's nervous.
Reminding a woman that she is cherished can include reminding her that women like her are rare, and that she is the whole world to her partner. It can also include telling her that she is one of a kind. Telling her that she makes her partner proud can include telling her that a partner wants to be supportive of her career and the choices she makes in life.