I haven't (yet) used a magnifying glass when creating artwork, although the thought has occured to me on several occasions. Perhaps it's only a matter of time with my love of detail and my middle-aged eyesight. I'm sure if I was doing this kind of thing I'd be into the magnifying glass.
Dalton Ghetti carves tiny sculptures in the tips of lead pencils. Yes. Really, he does. Regular-sized, ordinary pencils.
I had his stubby pencil alphabet as my computer wallpaper for a while. I changed it because I kept misplacing files amongst the shiny colors.
One of my other favorites is the saw, which uses the lead for the metal part and the wood for the handle part.
See more examples of his very fine motor skills here and here.