What helps improve a woman's libido?

Reduce tension. Libido has both psychological and physiological components to it, and stress brings about the same changes in one. Having a positive attitude toward sex and sexuality, one's partner, as well as managing one's physical and psychological stresses will help to improve libido.
Love and attention. Unlike a man, who's sexual response is immediate, women need much more time and attention to increase libido. Hand holding , kissing, foreplay can all help. There are many herbs and bio identical hormones that can also assist the process.