Also if you're using the plastic pop-bead sort of armature you need to do something to close the bottom of each foot and hand. After having to take a doll apart to redo it now I use a small piece of muslin tied with heavy buttonhole thread around the ends. If you don't do this, the glass beads will mysteriously migrate into the armature itself and play havoc with the rest of your doll.
If you're using wire or electrical cable/cord wrap the ends with some batting and tie it on with the heavy duty thread. That way the inside of your vinyl is protected. When I was making porcelain dolls and using wire armatures I would always wrap the whole thing in strips of batting, but that was to keep the wire from clinking against the porcelain. Might still be a nice way to finish off the inside of the doll though.