Sharpening a serrated-edge knife on an angle-assist sharpener like Spyderco's Tri-Angle, shown here, is possible. The blade is intended to be held vertical and stroked along the diagonally set stone while the other hand steadies the base. The two brass rods at left are intended to protect the left hand.

Sharpening a knife or other edged tool is, in theory, simple and straightforward. However, in practice it's often complex and arcane. Many people are baffled by the required skills, and few are familiar with the wide and increasing variety of sharpeners available. This article is a blueprint for action. As you read it, you can appraise your sharpening needs as well as your skill level and then choose the most appropriate type of sharpener.

We've concentrated on three sharpener types here, along with a variety of offerings for each type, which will probably lead you to concentrate on one of the three. Then, instead of simply visiting a nearby dealer,…