What I have now identified as rookie mistakes when making puppets:
1) Putting the hand-hole dead centre, when it should be further towards the back of the head than the front.
2) In general, focusing on the appearance of the puppet to the detriment of the flexibility of the puppet.
I got to try out the electric turkey carver on some couch-foam, before the 20-year-old device self-destructed. But it is a pretty good tool for foam-carving.