If you were to ask me what my favorite movie is, I would most likely mumble something foreign or allude to some esoteric film genre. The truth is, I’ve lost count how many times I’ve watched Clueless, the 1995 camp classic responsible not only for injecting a host of words-as-hand-gestures—Whatever, Loser—into pop culture, but also introducing millions of teenagers to the world of high fashion. Upon its release, my interest in clothes reflected that of my grunge-obsessed brethren. But, like my peers, I immediately embraced the bright, cartoonish, bubble-gum pop flaunted by Cher Horowitz and her equally style-whipped clique, who turned their big-screen high school into a walking, talking runway.

The woman responsible for the mass teen awakening is costume designer Mona May, also known for her work on everyone’s other secret favorite, Romy and Michele’s High School Reunion, as well as The Wedding Singer and Enchanted. A trained fashion designer, Mona’s eye for trends is impeccable, and with Clueless she created a look that persists today. L.A. boutique Confederacy recently joined forces with Francisco Costa to reproduce the iconic Calvin Klein dress Cher wears (the skimpy white one, at which her father frowns and says, “What the hell is that?”), currently selling on their website for a cool $916.

This year, Mona reunites with Clueless director-screenwriter Amy Heckerling and Alicia Silverstone on a new film, Vamps. If you haven’t been poring over film blogs, it’s a Clueless-in-tone comedy about beautiful vampire BFFs, with Sigourney Weaver as the vampire queen.

Here, a moment with Mona about those heady days and the making of an enduring fashion icon…

What were your references for the costumes in Clueless? Did Amy have a clear vision of what she wanted?
When Amy wrote Clueless, the current fashion was grunge. Her vision for the film was to show the rich, upscale high school girls of Beverly Hills. The costumes were to be like characters in the film.

Was the hyper use of color a reaction against grunge?
Yes, grunge is dark and sad so the color palette was very important to Amy. The clothes needed to be very bright and fun. I wanted the girls to be girls again, with over-the-knee stockings and Mary Jane shoes. We wanted to change the current look that was on the street and show teens how to have fun with clothes.

Were you influenced by catwalk trends?
Amy loves fashion and we had a great time looking into current European designers and what they were doing on the runways. It takes eight months to make, edit and release a movie. I had to intuitively pick the trends that I felt would still be current in eight months time. We also had to make sure the trends and fashions translated into the lives of teen girls. It was a great collaboration and I think it worked well on screen with the language and sets that Amy had visualized.

Did you have any idea of the impact it would make on street fashion?
No, we had no idea what an impact the movie would make on young girls all over the world! I was trained as a fashion designer and was just breaking into costume design, so I was in heaven blending my two passions and creating a runway show for teens on screen.

When did you first realize that kids were copying the Clueless style?
I saw girls in L.A. and Beverly Hills wearing the Clueless looks, then Karl Lagerfeld sent models down the runway with cell phone carriers that we designed for the movie. Then it was all over the magazines, including Vogue and Women’s Wear Daily, that Clueless was the fashion movie of the year. It was great!

Were there any kind of commercial tie-ins with the release of the film? Did any stores do special Clueless window displays?
Yes, lots of stores did Clueless window looks, but at the time we did not follow up with a line of clothes. We should have!

Do you believe that film inspires fashion?
Fashion is one thing and creating real characters on film that people can relate to is a whole other thing. It was wonderful to be able to work in these two worlds and bring high fashion onto the big screen.

Can you tell me what to expect from Vamps, fashion-wise? Should I be preparing for another image overhaul, à la Clueless?
Vamps will definitely have a Mona May/Amy Heckerling flavor, but it is a different movie. They are vampires and bring back looks from the past and mix it in the present. Fun!