While designing the appearances of the various gods as they will appear in The Olympians I had the hardest time by far figuring out Aphrodite, the goddess of beauty and love. She had to look stunning, even by perfect goddess standards, and at the same time have a air of danger about her. She's so beautiful that even the gods couldn't behave themselves around her. That's why, as soon as she stepped from the foam, Zeus married her off to Hephaistos; that way, at least if she was "off the market", so to speak, it would minimize the conflicts between the immortals.
For the longest time I couldn't get the design of Aphrodite to work, and eventually I came to realize that the problem was that I was drawing her as a blonde. Which is funny, when you consider that no less an authority than Botticelli, painter of probably the most famous image ever of Venus/Aphrodite envisioned her with brown hair. She was a mediterranean beauty whom even the ancient Greeks believed came from somewhere out of the far east. In other words, probably not blonde. Once my version became a brunette with olive skin everything fell into place.
After all that work, Aphrodite only makes a one-paneled, unnamed cameo appearance in Zeus. She plays a somewhat larger role in Grey Eyed Goddess, but her real chance to shine is a few books down the line.