And for those reeeally teeny-tiny items, you should also have a set of "Swiss Files", sometimes called "needle files". Very small, fine teeth, and can do some amazing things that large or full size files can't do.
Files are a great tool in all sizes !!! Husky makes a great seven piece precision needle file set with each file having a knurled round steel handle (built into file) along with a collet tightening handle with the set that fits in your back pocket case and all. No they are not paying me for this, just love it !
Another element of file care my uncle taught me is to be sure the file doesn't overheat. It's tempting to go hog wild, rapidly sawing back and forth when there's a lot of material to remove. But this generates heat, which can dull the file. Better to use deliberate firm stokes, and pause between each one.