It starts with a flat piece of sheer nylon fabric, the finer the fabric the more realistic the result will be. I use 400 needle flat knit fabric, 15 denier. The template is a simplified tracing of the doll's leg and its length is from the doll's toes to the leg joint. There is some shrinkage of the stocking in the process and you may find the stocking come up short a little...its practice.
For more sophistication like a reinforced toe and heel, stop the sewing about 8mm from the end of the template. With the needle firmly down, raise the foot and slide under a rectangle of sheer fabric. Fold the remaining over the template but under the foot. Drop the foot down and continue sewing down and around the edge of the template.