When it comes to recession indicators, look no further than the resurgence of this iconic hairstyle. Here’s why Olsen twin-inspired waves are the ‘cool girl’ hair trend making a comeback.

They would sit down soaking wet hair, get that full blowout ... Related: The Unofficial Guide to Mary-Kate and Ashley Olsen's Hair Evolution Never miss a story — sign up for PEOPLE's free ...

When it comes to hair inspiration, Mary-Kate and Ashley Olsen are always at the top of Hillier's list. "The Olsen twins are iconic, and their hair will forever be. Blonde with high contrast yet ...