Here, freelance fashion writer Emilia Petrarca on the diffuser she has used since she was 13 years old. Growing up, I would come home from haircuts sobbing because my hair would get totally botched.

The DevaCurl Devafuser Universal Diffuser For All Curl Kind ($50) has 360-degree airflow, which dries hair faster than traditional diffusers. The ceramic inner core allows the product to create ...