How to Braid Cornrows
The easiest way to create neat cornrows is to dampen your hair and part a front section. Take a small section of hair from this section and divide it into 3 strands. Twist the hair twice like you would for a normal braid, then add hair from below the braid into the middle strand. After each twist, add a little more hair to whichever strand is in the middle. If you run out of hair to add, continue with a regular 3-strand braid.
Wash and detangle your hair. Use your normal shampoo and conditioner to wash your hair. While its damp, detangle your hair with a leave-in conditioner and brush, then apply an oil or butter to lock in moisture. Your hair will be much easier to braid when it is moisturized and free of tangles. Examples of oils or butters you can use to keep your hair moisturized and tangle-free are coconut oil, argan oil, jojoba oil, shea butter, or aloe butter products. Check the natural hair care aisle at a pharmacy or beauty supply store to find these products. If your natural hair is tightly coiled, you may also want to blow dry your hair before you start braiding. Blow drying will help stretch out your curls and give your cornrows a neater look. Part your hair in rows from front to back. Use the end of a rat-tail comb to part your hair in rows from your forehead to the nape of your neck. You can part your hair down the middle first, from your forehead to your neck, then divide each side section into 1-3 more rows. Secure the rows in place with small-tooth clips or with bobby pins. If you don't want a middle part, create 2 parts near the middle to make a row right on top of your head, then make more rows on the sides from there. Try to make your parts evenly spaced so that your rows are about the same size. Divide the first row into 3 small sections. Begin with a row of hair on top or on the side and unclip it. Take some hair in your fingers from the front near your forehead or ear. Separate that row into 3 even sections with your fingers: a left section, center section, and right section. You should use both hands to do this, with 1 hand holding 1 section of hair, while the other hand holds 2 separated sections of hair. Before you start braiding, you may want to add a bit of edge control along your hairline. This will help you grip the hair easier, tame flyaways, and keep your cornrows neat. Make the first braid stitch. Starting with either the left or right section in your fingers, move it over and on top of the center section, replacing the center with it. Then move the section on the opposite side over so that it is in the center, and switch the current center piece with that side. At all times you will still have 1 hand holding 1 section of hair, while the other hand holds 2 separated sections. Add a small section of hair from the row underneath to each braid stitch. Repeat the above braid stitch technique, adding a ⁄ 2  in (1.3 cm) section of hair to each stitch as you go. Every time you make a new braid stitch, add more hair from the row, and continue until you reach the nape of your neck. This will keep the braid attached to your head. If you don't add more hair with each stitch, the braid will be loose and come out from your head instead of being in a cornrow style. Instead, you want to French braid each row. Finish the braid once it's off your scalp and secure it with a hairband. When you get to your neck, you won't have any more hair to add into each stitch. Simply finish the braid until you've used up the rest of your hair. If you want, you can secure the braid when it's finished with an elastic hair band, rubber band, or small barrette. The length of the end of your braid will depend on how long your hair is. Continue the same braiding technique for each row on your head. Unclip the next row of hair on your head. Repeat the process: divide that row into 3 even sections at the front near your forehead or ears, French braid it until you reach the nape of your neck, braid the remaining hair, then secure the braid at the end with a hair band. Try side-swept cornrows for an elegant look. This design is similar to front-to-back cornrows, but it's turned on its side. Create 3 even parts horizontally, beginning at one ear, rather than vertically. Clip all but 1 section out of the way. Begin each braid at the side near your ear, and French braid each row by adding new hair from the row with each stitch. All of your braids should be braided to one side. Bring your braids either to your left or your right, whichever is your preference. These braids will end at various places on the other side of your head. Secure them with elastic hair bands just as you would regular cornrows. Go with swirl cornrows to try something unique. For a little twist on traditional cornrows, part your hair starting in the front near your forehead, but instead of going straight back, curve the line to 1 side of your head and then back again toward the other side. Create 4 more parallel parts so that you have 5 total rows that appear to swirl from the front over and around to the back in uniform curved lines. Then create curved cornrow braids within the parts. End the curved sections of hair at the nape of your neck on the opposite side from where you first headed when you curved the lines. When you're finished with each braid, you can join the braids together in a low side-ponytail if you like. Braid long cornrows into a high ponytail. If you have long hair and like to wear it in a high ponytail, try braiding your cornrows only to the beginning of where you start your ponytail. Create parts around the perimeter of your hairline and braid them back. Stop each cornrow at the point where you place your ponytail in the back center of your head, instead of at the nape of your neck. Feel free to braid the rest of each row, rather than cornrow it, so that your ponytail consists of braids. This style also looks good with different sized cornrows, so you can make it easier on yourself by simply creating and braiding rows 1 at a time. Try cornrows with zig-zag parts for something totally different. Create parts in zig-zags by starting at the front by your forehead and going back and forth in 2 in (5.1 cm) lines all the way to the nape of your neck. Then braid your cornrows straight back as you normally would, simply using the hair sectioned off within the zig-zags. You can combine this parting style with other techniques such as the side-swept cornrows, or keep it simple by doing only 1 or 2 zig-zag parts while the rest of your parts are straight. 
Wash and detangle your hair. Part your hair in rows from front to back. Divide the first row into 3 small sections. Make the first braid stitch. Add a small section of hair from the row underneath to each braid stitch. Finish the braid once it's off your scalp and secure it with a hairband. Continue the same braiding technique for each row on your head. Try side-swept cornrows for an elegant look. Go with swirl cornrows to try something unique. Braid long cornrows into a high ponytail. Try cornrows with zig-zag parts for something totally different. 