We all know how challenging it can be to maintain silky straight strands in the heat of summer—so when we spotted Ashley Greene’s weather-defying hairstyle at the premiere of Wish I Was Here, we just had to reach out to her hairstylist, Richard Collins, for the inside scoop.

Relying on Leonor Greyl products for a super-sleek finish, Collins first massaged Mousse au Lotus Volumatrice ($46; leonorgreyl-usa.com) to the star’s wet hair and pulled it from the roots to the tips, using a “less is more” approach as he applied. “I really liked this mousse because it wasn’t heavy; it was really light but still smoothed the hair,” he tells us. “Then, I blow-dried her hair and went back over it with a flat iron to make it sleeker and tighter.”

Collins moved on to Éclat Naturel ($46; leonorgreyl-usa.com), a protective styling cream, and smoothed it on top of her hair and along the bang area for a bit of shine. He turned to the ultimate frizz-fighting weapon for his next step: a toothbrush doused with hairspray, which he used to tame flyaways along her hairline and around the ear.

“Lastly, to finish the look, I took some Éclat Naturel on my fingers and ran it through the hair around her face, concentrating on the ends and piecing it through a little bit, but made sure it wasn’t too saturated,” he adds. “This kept the look shiny, instead of greasy.”

Check out more summer hairstyles we love in our gallery!