Really the question is why you WOULDN'T want to look like a greek goddess for Halloween. After all, many of them, like Aphrodite and Eos, are damn near perfect in all their glowing gorgeousness, at least we assume from the artistic depictions.
If you want to look ravishingly beautiful in a higher-than-thou way this Halloween, check out this video to learn how to create a greek goddess costume with lacy white fabric and golden leaves.
This is a simple draped costume that can be made in less than an hour.
Crushed Stretch Velvet: Jo-Ann Fabrics
Gold Leaves: Michaels
Chantilly Lace: Hancock Fabrics