While it is possible to purchase ready-made doll parts from a number of manufacturers, making your own will lend a more personal touch to your creation and give the finished doll much more personality. These instructions are for doll parts that will be attached to a sewn body.
Knead the clay with your hands until it is pliable. This is also a good time to blend different colors of clay together to achieve the preferred skin tone if the manufactured ones are not exactly what you want.
Make the shape of the head by pinching off a portion of clay, rolling it into a ball and then into an egg shape. Sculpt the neck by pushing and pulling clay from the back of the head down so that it extends behind the chin. Push and pull the clay to form the forehead, cheeks and jawline.
Roll a small piece of clay into a cone and then press it into the center of the face for the nose, smoothing the sides down over the cheek area. Draw in the lines of the eyes with a pointed tool and then roll out a tiny coil of clay to make the lips and ears.
At the base of the neck use a carving tool or the back of a butter knife to inscribe a channel just up from the edge. This is where the fabric will be drawn up to attach the head to the fabric body, making sure it doesn't just slip off.
Moving on to the legs, roll out two coils of clay up to 4.5 times the length of the head. This will vary depending on the planned height of your doll and where you plan to attach the legs. Stretch out and fold up one end of each leg for the foot and sculpt the calves, knees and thighs. Inscribe any details into the feet and legs, then carve the channel at the top of each leg just as you did on the neck.
Roll similar coils for the arms, up to 3.5 times the length of the head, flattening one end of each for the hands and sculpting the forearms, elbows and upper arms. Add as much or as little detail to the hands as you want and scribe the connecting channel into the upper arms.
Pose the arms, hands, fingers and legs how you will want them for your finished doll. If necessary, cradles of crumpled foil can be used to help keep the clay from loosing its pose while baking.
Bake the parts as directed on the clay packaging on either a glass or metal tray.
Once completely cool, paint on any details such as eye and lip color and any skin tones desired and attach to your doll body.
You can purchase clay tools or use household items like toothpicks, scissors and a pairing knife. Your hands are the best tools for most of this project, anyway. Armature wire can be inserted in each limb before baking and connected within the doll body for more purposeful posing once assembled. To attach any decorations to the polymer clay (beads for eyes, for instance) use a 2-part epoxy for the best hold.
Cover the unused clay with plastic wrap to prevent it from drying out. Even though polymer clay is generally nontoxic, it is best not to share tools used in clay work with those used in food preparation.