I don't do this very often lately. There are too many other things to focus on and for my little brain, this can't be done well without a certain level of obsession, and that obsession has to involve the aim of achieving some new level of skills or understanding. New challenges stimulate new neurons. Sometimes it is good to be thoughtful before doing more of the same.
But for all that, the creation of a lovely arch for a violin back is the most satisfying and focussed manual work I've ever done. Worthy, almost, to be done without bothering to finish the instrument, just as an exercise in the marriage of volumes and lines, and the resolution of art with engineering. And the flirtatious engagement between hand and eye.
And that doesn't even begin to touch upon the subtleties in the production of a sweet and satisfying sound.