Watch Nancy O'Dell Find the Perfect GG Dress!

ET's Nancy O'Dell let cameras inside her recent dress fitting for her 2014 Golden Globes dress in Los Angeles, where she tried on two gorgeous Marchesa gowns perfect for Sunday's star-studded red carpet!

Deciding between a bright blue lacy creation and a stunning red embroidered gown, Nancy only has one requirement -- that her dress has a train!

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"I always have to have a train. I love trains on the red carpet," Nancy dishes. "They're kind of tough to navigate but it's worth it. It's actually a good conversation opener. If Leonardo DiCaprio steps on your train and you almost fall, then he feels guilty and he needs to do an extra special interview with you because of that. So, I love trains for that reason, and they also add a certain drama to the gown."

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Click the video to see both of Nancy's elegant choices up-close, and to hear Marchesa designers Georgina Chapman and Keren Craig dish on what makes these specific two gowns so special!