How accurate are facial reconstructions based on the skull alone really?

I think they’re fairly accurate and have often aided law enforcement in ID-ing victims of crime.
I believe there are averages of flesh thickness at certain points on the skull which the artists go by when applying clay to the model.
It seems to work.
When they recreated Richard lll’s face after they unearthed his bones, I was surprised at how close it was to the paintings and paintings are something I usually question for accuracy.

There have been done a few in Dutch murder cases (by English or Scottish ‘artists’), that looked pretty accurate (after they ID’ed the victims).
Not spitting images, to be fair, but good resemblances.

I expect skulls don’t tell you how much flab or sag someone had, or their nose shape, facial hair, eyebrows/lashes/eyes, wrinkles, complexion, etc.

There are aspects to the bone itself which can determine age. From that they can then approximate reasonably well.

No idea but it’s hella cool to watch.

Kathy Reichs is the forensic anthropologist who was behind the tv show Bones. She wrote several books. Some are non fiction, several are fiction based on her factual knowledge. She is highly descriptive. You could learn a lot about the processes, even from her fiction.

They know about the muscles required, and how many there are. They build the face muscle by muscle, then apply skin and fat as in reality. And they have been doing it for years so it must be quite accurate.