A straightener (or flat iron) is a heated tool that is commonly used to straighten and smooth hair by changing the structure and texture of the hair. Contrary to its name and original purpose, it can also be used to curl your hair. The curls and waves you can achieve with a straightener will not be as tight or defined as the curls achieved with a traditional round curling iron, but are instead bouncy, soft, and natural-looking curls.
Start with dry, brushed hair. If you are using heat protecting spray, apply that to your hair.
Heat your straightener. The size of your straightener will determine the size of your curls; a wider straightener will produce larger curls while a smaller straightener will produce tighter curls.
Take a lock of hair. The smaller the section of hair that you use, the tighter your curls will be. Open the straightener and place the lock between the plates, but do not close the iron.
Wrap the lock of hair around one of the iron plates two to three times, then close the iron. If your hair is longer, you may have a "tail" of hair hanging from the end of your closed iron, which is fine. Gently slide the iron down the section of hair while rotating it outward.
Mist hair with hairspray to set the curl.
Practice caution when using a straightener, as it can burn your skin, hair, or other things with which it comes into contact.