Jessica Simpson is adding lingerie to her design palate with a line called Jessica Simpson Intimates. Simpson's new collection will include bras, panties, panty-line erasing shape wear and sleepwear, joining her already successful collections of handbags, sunglasses and swimsuits.

"I like different lingerie for different occasions," says the singer-designer. "I think that's the best thing about it; you can feel sexy or girly depending on your mood. Lingerie makes you feel beautiful from the inside out. I think if you start with something that fits correctly and is comfortable and fashionable it will only compliment your look."

So what does she say is the biggest lingerie faux pas?

"I think it's a mistake when women wear the wrong pieces of lingerie with the wrong outfits, like a slim fitting dress with no shape wear underneath!" she told Women's Wear Daily. "I personally think shape wear should be considered a red carpet staple, and because of that, I'm adding a stylish assortment that women will actually want to wear, into my collection."

The Jessica Simpson Intimates line is due on store shelves in Spring 2009. Her first-ever country album is expected to come out this fall.