1.Wash and condition the hair thoroughly. After washing, blow dry the hair so that it is straight with no styling products (do not grease or saturate the hair with any other oils).
2.Depending on the style of the extensions, part the hair according to a specified pattern. For example, if you are doing a full head, part the hair from crown to crown; if partial extensions are used, part the hair straight across from the base of the neckline to the crown.
3.Cornrow each parted section from left to right---or in the case of a full head of extensions, cornrow the hair around the head in a circular pattern. Be sure that the braids are tight enough to hold the extensions. The style will not last with loose braiding.
4. Measure the extensions and cut them to fit the cornrow. For thicker and fuller extensions (and also depending on the quality of the hair), the hair should be doubled and in some cases tripled to increase fullness. Also in this step, you must cut and measure the thread and hook it to the needle.
5.Sew each line of extension to the cornrow by weaving the needle and thread through the thick lining of the extension as well as through the individual cornrow. This process connects the extensions to the cornrows. Be sure to pull the thread all the way through for maximum hold.
After sewing the extensions to each cornrow, tie a small knot in the thread---leaving a tiny bit hanging from the extension. This is done so that the extensions can be removed easily.
6.Style the extensions and/or remaining hair. Add moisture to the scalp if desired.