The sixth and final season of HBO’s “Girls” premieres Sunday night, and, if you’re like us, you’re probably trying to soak up all things Hannah, Marnie, Jessa and Shoshanna before the final chapter closes and leaves us all heartbroken and counting down the days until the movie (seriously, it might be a thing).

Lucky for us, the hair on “Girls” was often just as fascinating as the characters themselves (and was integral in helping tell their stories), which gave us an excuse to call up Sherry Heart, the official hair designer of the series, and gab…