These. A whopping $4 gets you files that actually
cut, meaning you don't have to sacrifice stock removal speed to get a reasonably smooth finish, as you do with diamond grit files and other abrasives. The one set does it all.
They are anything but high quality, mind you - they're stamped jobs sold cheap after being imported even cheaper. But they still
work. Any failures in the stamping result in shallow teeth - "dead" spots on a cutting stroke that have no negative impact on the final finish. I also found them a bit uncomfortable to use without trimming some flash off of the crappy plastic handles. [curmudgeon] Seems quality hand tools are specialty items, nowadays, so that's the price you pay to... not pay a higher price. [/curmudgeon]
Also note that regular files, as opposed to the diamond grit most wargamers seem to use, only cut in one direction (the "push" stroke, in almost every case). Sawing at materials like one can with abrasives doesn't speed up the process, it only dulls the files. While you're shopping, get yourself a brass brush (
HF has them for <$1) or a spring steel file card (a bit more expensive, but doesn't splay out as quickly) to help clear the teeth - files, whether cutting or abrasive, clog much faster with soft materials like styrene and white metal. Luckily, teeth clear more quickly and easily than grit, so a few swipes every now and again will keep you cutting at full efficiency.
Finally, a general thought on file sets: Bigger =/= better. If you can find the same files in a basic set of 5 and an expanded set of 12, get the 5. Hell, get
two of them, in case you lose one - it'll cost the same. As with sculpting tools, variety seems ideal until you actually start using them, after which you generally find that you're always reaching for the same two or three tools. There's little you can't do with a single half-round, but you'll have an easier time if you also include a few other basic shapes.