Miranda Cosgrove's Must Haves, From Luxury to Drugstore

"When I fly, I sleep — I'll often be asleep before the plane even takes off," says Cosgrove. "But when I wake up, my hair's a wreck, so I've always got a good brush in my bag."

She's a fan of this fancy Mason Pearson Detangler All-Nylon Hair Brush ($150), which stylists regularly say is one of the best that money can buy. The brand has been around since 1885 and has developed a cult following despite the hefty price tags on its products. This brush, in particular, is made with soft nylon bristles that glide effortlessly through the hair and won't cause frizz on wavy or curly textures, and Cosgrove loves how it can transform her knotted, post-plane hair into something smooth and shiny.