If there is one thing I've come to realise, it is that the bigger the tool, the more wood it grabs and tries to remove in one go. This is particularly the case when hollowing a vase or large bowl.
My main 'got to' tools of choice used to be the Exocet or Woodcut Pro-Forme. I've since bought a 8mm disc cutter and the smaller bite size makes it much easier to wield.
But enough of that, I've just found this YouTube video of someone making a Spoon Carving tool from an old spanner, and apart from the fact i don't possess a Die Grinder, it does not actually look too difficult to make. And of course, spanners come in all sizes.
Remembering that recently there was a discussion started by Pete (bodrighywood) looking for a Japanese Hook Tool, I thought that I'd bring this to everyone's attention. Someone might like to try make a Ring Tool from a spanner, likely to be much stronger than the current ring, welded, to the bar, type we can buy.
https://www.youtube.com/watch?v=TY-h3qRp308