The hand held file guide is good for sharpening your edges, use it to file only the side edge; do not try to use it on the base edge. For filing the base edge, you need to get a decent file guide that is set at the angle you want (1 degree is standard for most riding, but they make them up with higher angles. The idea of using the Sharpie pen is sound....it gives you something to visually monitor your progress and helps prevent removing too much metal. Base edges need to be as uniform as possible, so be careful and take your time. Also, you want to maintain a 89 or 90 degree angle on your edges so if you have a 1 or 2 degree base edge bevel, be sure to match that on your side edge. An ideal free ride set up is a 1 degree base edge and a 2 degree side edge; this makes a very sharp, 89 degree edge that holds it`s edge well on ice.
You can ruin a board very easily by messing up the steel edges, so do not go cheap on this equipment, get good stuff and learn to use it properly.
A diamond stone or any knife sharpening stone is great to lightly hone down the filed edge; use a light touch and just go over it a few passes to remove file burrs. The hand held file guide is ideal to take in the car to run a few passes down your edge to get a good sharp edge again. I run one down my edges every couple of weeks to maintain a sharp edge.
So I should not use this for the base edge then? One side is 90* the other is 88*, one question does anyone know if I want to use the 90* side should it be face up or down? And I know it has been gone over but I don't want to ruin my edge, I should use 90* side right? I ride either Mt. High or Snow Summit and it seems to be pretty icy or at least real hard packed most times.