What it is: A multipurpose straightening iron that straightens, curls and smoothes and leaves it shiny. Who it's for: All hair types.What it does: This flat iron allows you to quickly straighten even the thickest hair into super-seek straight looks, or to add a bit of wave or curl to your hair. How to use: To straighten, hold the iron horizontally. Clamp hair at the root and slowly pull through to the ends, slightly beveling toward the face to prevent static. To curl, hold the iron vertically. Clamp hair midway through the section and pull forward to the ends. The slower you pull, the greater the curls. For waves, pull through hair more quickly.