Here is a couple pointers on using files
1 Grind off your edges, slightly grinding off your edges on your flat file or pull file
will help keep them from making a dig into your metal , also letting you get closer to vertical edges with out hitting them
2 Chalk , rubbing chalk into your files will keep small metal particles out that can rough your metal, it will make your files last longer stay sharp longer and cut better
3 always brush out your files when switching metals or when your done for the day, reapply chalk before starting the next use
anyhow hope these tips helps someone