A good standby for women's Halloween costumes is a historical themed costume depicting a woman from ancient Egypt or Arabia. Dress as the queen Cleopatra or as a harem girl straight out of the Arabian Nights for an exotic and elegant addition to any Halloween soiree.
One type of women's Egyptian costume is a classic white robe with gold adornments, but there are also black robes to depict a dark princess or goddess. These can be dressed up with an Egyptian style straight black wig for authenticity and dark make-up around the eyes. To depict a more dangerous, frightening beauty, dress as a mummy in a tattered white robe but with smoldering come hither eyes.