For a very long time (which is not that long, I have not worked on dolls that long yet) I was just glueing the dolls faces on. As you can see, in the time frame from Rodrik to Hedwig, the faces are a bit flat and they have ruffles around them to conceal the seam.
Only recently I overcame my fear to ruin a whole doll and tried a different system. Since I am not great when it comes to explaining how this works, I took some pictures while working on my latest dolls.
I always start with the dolls face, since I am arranging the rest of the pattern on how big it turns out in the end. When I start sculpting I always have a plan but nothing is set in stone so things and sizes can always change. When I am done with sculpting I add a ridge around where I want the fabric to start.
When the pattern is made and cut out, but before anything is sewn together, I assemble the parts that go around the head and tightly put a string around them. The string should slide into the ridge around the sides of the head. Sometimes I use glue before that but it is not always needed. This part in general is very tricky and I am still trying to optimize it for myself.
And this is how it should look from the front after everything is sewn together. The string in the back should sit tight and after stuffing the body there should be no way for it to fall off or get torn off.
And this is it, stuffed and painted. The problem that this new way of adding the face brings is that there should be a similarity in the colours from the paintjob on the face and the fabric. There are no ruffles to conceal differences. Which is a challenge, especially when using a fabric with a pattern. It is a hard choice if you wan to add the fabric pattern or just match the colours of the fabric. This cat lady got parts of the pattern painted on its face. But Cordelia for example has no pattern on her face and I only tried to match the colours.
I hope this post made the whole process a bit clearer. It is a bit hard to explain.