First you take a wire hanger and fashion a square out of it and twist one end because you will need to be able to slip the doll off. I did not do it very well and regretted it while making it, but I had a toddler helping and just did it with my hands. I would definitely redo it with some pliers to make it more stable and square.
Start the arms and tie on a loop crossways on the frame.
Put on plenty of yarn and tie off to original tie string.
Then do the same procedure up and down for the torso, head and legs.
Then take pieces of yarn and tie at the neck, waist and wrists of the body. If you want a man, split the bottom in two and tie at the ankles, but I am making a lady or an angel, so you wouldn't have to tie any of the leg portion.
Slip a sting of yarn through the head and tie it down to make a round head.
Slip the head off the frame. Then you can either slip the limbs off the frame or you can cut them off.
Then tie the loop from the head into a hanging loop to hang on the Christmas tree and there you have a Christmas Yarn Doll. You could make clothes for it or some wings & halo. But this is the base.