Jessica Simpson: I'll Wear a Low-Cut Wedding Dress

By Lesley Messer

04/15/2011 at 01:10 PM EDT

Jessica Simpson may be a fashion mogul, but she's still at work on her most important look yet: her wedding dress.

"It's definitely going to be beautiful," the singer, who is engaged to former NFL player Eric Johnson, tells PEOPLE. "I want it to be different from what I've had before. I have a lot of tear sheets!"

Still, Simpson – who says she'd love to have a "Carrie Bradshaw moment" trying on lots of gowns – often gravitates toward v-neck or scoop necks, which flatter her physique and help her avoid looking "top heavy."

Besides, "I like my collar bone," adds Simpson, 30. "I have a long neck, so I like to show off my décolletage."

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As for the color, "I haven't really thought about it," Simpson confesses. But, "I do like the romantic feel of a lighter color."

While she focuses on her dress, Simpson's bridesmaids will be busy choosing their own ensembles. "I definitely would want all my bridesmaids to be in everything different," says the bride-to-be. "Just [to reflect] what their personalities are."

For now, though, with so many of the plans still up in the air, Simpson doesn't even know when the nuptials will take place – or where.

"It’ll definitely be somewhere warm!" she says. "Once I get what I want my dress to look like. We'll set a date."

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