What it is: A large-sized round brush that easily straightens thick, curly hair or gives shape to straight hair. What it does: Its supple bristles provide a better hold on the hair for easy drying. Hair is easier to straighten and appears softer and shinier, with frizz under control. How to use: For more hair volume, pull up a length of hair from the top of your head and roll the brush up. Position the brush and then brush backward and dry.