I recommend sewing doll bodies and their clothes by hand for ease of manipulating the small pieces and for a finished quality look.
I hand sew all most of my dolls and their clothing using either one strand of quilting or buttonhole thread. If the doll is not going to have much rough use you could also use cotton / polyester thread which is less expensive. Be sure to double your strand of yarn when sewing with it, though.
I knot the thread on the underside of seams where it will not be seen. When at the end of a thread and have made my knot I cut the thread leaving one quarter inch hanging just incase the knots loosen.
I keep in mind that my grandkids will be putting these clothes on and off their dolls and stuffed animals, so make the sewing as strong as possible.
Another hint for your handsewn items is keep an outfit all together in a half gallon size clear ziplock bag.
For embroidering features on doll faces and for embellishing clothing I use either 6-strand floss, or for a small design I separate a sewing length of floss in half so it is just 3 strands.
To knot on yarn wigs I use either 4-ply wool or acrylic yarn. My recommendation here is to make sure your choice of yarn for wigs washes nicely, so you can use the washing machine to launder the whole doll.
Sewing techniques
Index of Special Doll Making Techniques - Tutorials
Decorative Edging for Doll Costumes
Contrasting Top Stitching for Doll Costumes
How to Make Rolled Hems
How to Knot on Yarn Doll Wigs
Article and Photo Credit Susan Kramer
