This is a good 'how to' on a lingerie cake, uses box mix. I would stick with simpler icing design though. You could use those pearl looking sprinkles to decorate with! Or roll out the pre-made fondant if you're feeling really adventurous.
Women's Bra/Swim Suit Top Cake Balls. To make your own like this, use white dipping chocolate with chocolate coloring. For delicious dipping chocolate, use Chocoley Bada Bing Bada Boom Gourmet Compound Dipping Chocolate (available in dark, milk & white) from Chocoley.com.