How To Straighten Hair Quickly
Straightening your hair using a flat iron takes time, sometimes more than an hour if your hair is extremely thick and curly. Not everyone has that time to spare on hair every day, though. With some practice, you'll be able to straighten your hair in very little time.
Make sure your hair is clean.
Clean hair straightens better and doesn't get a burning smell so easily. Unless you have really oily hair, you don't need to wash it again if you have already done so the previous day. If it's been longer than one day, wash it again. If you don't have time you may use a dry shampoo.
Always use heat protection.
It may take a moment, but it is so much better for your hair. Spritz some hair straightening serum and brush it through your hair to protect it from the hair heat of the straightener.
Turn your flat iron on as high as you think your hair can take.
Do not exceed the temperature you are comfortable with. As a guide, try a low heat setting for fair, thin hair, a high heat setting for thick, curly hair, and a medium heat setting for something in between. If your hair damages easily, don't risk ruining it, and wait the extra minute or so for it to heat up. One good hairstyle is not worth months of repairing damaged, broken hair.
Straighten the bottom layer.
Do this layer, and possibly the next, quickly, and only go over them once. No one will see these unless you are putting up your hair, or it will cause a puff to the top layers because of a pony mark or something. Once you are done with the bottom, let down another layer, and straighten it. Repeat until all of your hair is straight. This actually does save time because you will be straightening smaller sections at a higher heat, thus requiring less time on each section.
From : www.wikihow.com