Rick Weissenborn of Tools4Boards demonstrates edge filing with various Tools4Boards Metal file technologies along with some good tips on basic edge tuning.
Note that metal files remove more material than stones or diamonds and are used to set initial edge geometry or re-establishing very dull or roughed edges. Follow with a progression of stones or diamond files and remove the hanging burr on the base edge formed after filing the side edges. Don’t forget to plane or cut side walls that may interfere with the stone or file’s ability to cut the side edge. Also note that work hardened edge sections formed when hitting rocks or other hard objects, require using a stone before the files. Otherwise, your files will be dulled by these hardened edge sections.