Making your own sex doll at home can be quite involved and should be done with a lot of attention to detail, especially concerning the type of materials to be used, as well as safety and hygiene concerns. It can be a fairly basic creation of your own if you want, however, it should be acknowledged that sex dolls made by manufacturers are specifically built for durability, safety, and realism. If you want to pursue making your own simple version however, here is a basic process you can follow:
From: Yeloly

Here are the things you'll need:
For the Body
Old pillows
Foam padding or sponge
Cotton stuffing
For the Skin
Soft, stretchable fabric (e.g. Nylon, spandex or cotton)
For Adhesives & Fasteners
Sewing kit (needle and thread)
Fabric glue or hot glue gun
For Plastic Bags or Balloons
To give specific body parts shape and firmness
For Old Clothing
To dress the doll
For PVC Pipes or Bendable Rods (Optional)
To build a simple skeleton
Tools
Scissors
Measuring tape
Here are the steps to create a basic sex doll at home:
Make the Body
Torso: A big pillow, or some combination of foam padding and stuffing, makes up the torso. Sew it into a cylinder, wrapped tightly with fabric.
Arms & Legs: Small pillows or tightly rolled fabric stuffed with cotton will make good arms and legs. Sew these to the torso, making sure they are secure.
Shape Key Body Parts
Breasts: Small plastic bags or balloons can be filled with water or air to create breasts to the size of your choice. Sew them onto the torso, wrapping them in fabric.
Buttocks: Similarly to breasts, the buttocks can be made from balloons or plastic bags stuffed with stuffing material. Sew these onto the lower back of the torso.
Cover with Fabric
Cut pieces of stretchable fabric big enough to fit over the entire body, including the limbs. Sew the fabric pieces into a 'skin' to cover the body, remembering to leave enough openings to get the body parts in. Then, place the body parts into the fabric 'skin' and sew the openings shut.
Build the Skeleton (Optional)
You may use PVC pipes or bendable rods to build a skeleton structure inside the doll if you want something with a little more firmness and support. This is best done before the body parts are put into the fabric skin.
Add Features
Flesh out hands, feet, and facial features using more fabric, or old clothing, sewing it carefully onto the appropriate parts.
Dress the Doll
Using old clothing, dress the doll; this adds realism and also helps it to keep its shape.
Points to consider and warnings
Hygiene: Any materials you use should be thoroughly cleaned. The doll should be easy to keep clean once it's made – removable covers will make washing much simpler.
Safety: Any materials used should not cause allergic reactions. Make sure there are no sharp edges.
Durability: A doll that you make yourself at home is not going to last anywhere near as long as a professionally made doll. Be prepared for wear and tear and regular repairs.
Realism: You will not be able to make a sex doll at home that comes close to the level of realism and function of one that has been manufactured professionally. Your expectations should reflect this.
Ethics & Privacy: You should carefully consider how you will feel about making and using a homemade sex doll and whether any other people are going to be affected by it and whether their privacy can be maintained.
In conclusion, it is indeed possible to create a rudimentary sex doll at home using common materials, but you should be prepared that it will not be anything near as realistic or as high quality as a manufactured one. If you intend to do so, you should be concerned with hygiene and safety and maintain realistic expectations about the longevity of the doll.