Handyman's Pocket Book: Sharpening A Carving Knife.

A steel is generally used, and the correct method used by butchers is to move the knife towards the steel, not away from it.  It is rather more awkward until you acquire the knack, but it gives a better edge because the wire edge is removed.  After a time the steel will fail to turn up a good edge, and it becomes necessary to grind the knife.  When this is done it should be held to the grindstone at an angle about midway between that formed by the steel and the flat side of the blade.  If a grindstone is not available a file can be used, though it takes longer.  Hold the blade on a block of wood with the edge slightly overhanging, and work the file with a sliding movement towards the edge, again at an angle about half that used by the steel.  If you have a stone step to your house you can often use this for rubbing down a knife.  A piece of paving stone on which emery powder is sprinkled is useful.  Add a little water to the powder to form a paste.