Bevels are measured in degrees, and to achieve an accurate and constant bevel along your edge, a file guide is used. A good file guide is a solid sleeve that your file slides into that guides the bevel along the edge. A good all-around base bevel is two degrees, which will prevent you from catching your edge, while still allowing you to turn on firm snow. Less bevel is more aggressive (tight steering), while more bevel is less aggressive (loose steering).
Now it’s time to even the side bevel to the base bevel. This will return your angle back to 90 degrees. If you leave the bevel where it is, you will have an obtuse angle, which is not sharp enough to turn.
Again, the way to achieve the bevel is to use a side edge guide. You slip your file into the guide and pull the guide down the length of the edge. This will give you a 90-degree edge that is beveled at two degrees (side and base) which is sharp enough to turn, but beveled enough to prevent catching your edge.
Clean It Up
The last step is to use your pocket stone again to smooth out your edge from any burrs left behind from the rough cut of the file. You don’t need the guides to use the stone, just rest the stone on the base and side edge and run the length of the edge. Use water (or spit) on your stone for the ultimate smooth edge.
If your board is brand new, make sure you de-tune (dull) the tip and tail, and make sure your bevels are set to where you want them. Just feel your edges after each day riding and use your stone to get rid of any burrs. This will take all of 30 seconds and will keep your ride smooth like butter. After several days of hard riding you may need to pull a file over your side edge just to get a good edge back. You won’t need to file your base edge again until you get your board base ground flat. Your local shop can help you with your edges and can even bevel them with a machine, but if you get the tools yourself, you’ll save time and money in the long haul.