To get Amanda Seyfried's sexy, of-the-moment braid, your hair should have lots of body before you start, says Riccardo Maggiore, owner of Riccardo Maggiore Salon in New York. Use plenty of mousse throughout (we like Garnier Fructis Style Volume Inject Mousse, $4) and a root lifter at the scalp for ultimate volume. If your hair is fine, you may even want to set it with Velcro rollers before you begin, he suggests.
How to do it: Make a deep side part. Pro tip: If you normally wear your hair to the left, switch to the right, and vice versa. Styling your hair in the opposite direction of what it's used to will give a bit of natural lift at the root, says Maggiore. Gather hair at the base of the neck and make a loose braid. Use an elastic the same color as your hair for a softer look. Then, with fingers, tug and separate the braid all over so it becomes messy and uneven—this final part is the key to the updated 'do.
Garnier Fructis Style Volume Inject Mousse available at drugstores.