Cornrows are braids that cover the whole head, with each resembling a French braid. They're very small and are close to the head. People often have these braids done at salons or in open-air markets in Africa, but you can do cornrow braids on yourself if you use some techniques and a bit of patience.
Set up a space to work on your cornrows. You must be able to see yourself in two different mirrors so you can check your progress as you braid. If possible, find a place where you can braid uninterrupted for several hours.
Determine the design for your braids. Most people do cornrows in a straight line all the way to the base of the neck, but you can create your own style easily. To create your own style, keep an eye on your mirrors as you braid, and use them to help you create curves and twists in your cornrows.
Divide out a small amount of your hair to begin with, and clip back the other pieces of your hair. The smaller the amount of hair you begin with, the longer your cornrows are going to last and the better they're going to look. Begin braiding at one ear and work your way to the other ear, unless your design doesn't allow this.
Take the small piece of hair and braid two twists. Then pick up a slip of hair next to your braid and add it in as you braid your next twist. Continue incorporating small pieces of hair into your braid until you reach the end of your scalp. Make sure to pull the hair tight as you grab extra pieces to keep your cornrows close to your head.
End the cornrow by making a simple braid with the remaining hair once you reach the end of your scalp. Secure it with a clip or elastic holder. Check your progress in the mirrors as you go to make sure your cornrows are as tight to your head as possible and that you're keeping true to your design.
Repeat steps 2 through 5 until you finish all your cornrows.
Put a small amount of hair oil onto a cotton ball and dab the oil into your scalp and your cornrows. Take care not to rub the braids and cause them to frizz.
Wear a silk handkerchief on your head at night to make your cornrows last longer.
Practice doing cornrows on another person a few times before you do them on yourself. It's a lot easier to get a good feel for what you're doing when you can actually see your work.
If you keep your scalp and braids moisturized, your cornrows can last as long as a month.