If you work on miniatures at all, you really owe it to yourself to get a good set of files. I own a set of Gale Force 9 diamond micro files, and they’re easily one of the best tools in my toolbox. They’re small, but surprisingly tough. The diamond coating insures that the files will work just as well on metal miniatures as on plastic ones (although plastic does require a lighter touch). Also, they come in a variety of shapes – flat, round, curved, square, and triangular – for dealing with a variety of surfaces and jobs. Utility-wise, they come in very handy at multiple tasks. With mine, I’ve:

• cleaned up flash and mold lines
• filed holes larger or pegs smaller to provide a better fit (particularly useful with plastic flight bases, which never seem to be sized properly)
• scored/roughened metal surfaces to help glue adhere better
• filing off old, stubborn super glue from older minatures
• added grooves and depressions to a bit to make it join with a different part

Of course, a good tool requires good care. Fortunately, these are relatively easy to take care of. I keep them in their plastic sheath when not in use, and after using them I run them lightly between my thumb and forefinger to clean off any material hiding in the filing surface. By keeping them clean and dry, you can greatly extend the life of your files.

There are also sets of larger files available, but for miniature work I prefer the smaller, more delicate micro files. They’re a good set of precision tools, and not badly priced for the amount of work you’ll get out of them.