More hair! Sewing hair is faster than tying on hair. It’s not as sturdy (it’ll come out if tugged too hard, so is not really suitable for dolls meant to be played with), but it forms a nice part, and will completely cover the head.
I first ran across sewn on hair on K and J Dolls and I liked it a lot better, because tying hair takes FOREVER.
The first thing to do is mark your part. You can have it down the middle, or on one side or the other. I used three pins to mark it, one at the front where the hair will start, one at the crown of the head and one at the middle of the back of the head where the hair will stop.
Cut lengths of hair twice as long as you want hair to be. Thread a needle with two strands of embroidery floss in a coordinating color. Secure free end of embroidery floss to head. Insert needle into head, draw up just behind front pin on head.
Put three strands of yarn between thread and pin, insert needle into head where pin is and bring out just behind first stitch.
Continue backstitch with three strands of yarn in each stitch until you get to last pin, making sure to keep hair seam lined up with pins. Tie off embroidery floss at side of head, under hair. Trim and style as desired.