Make it easy with electric
An electric knife sharpener is an easy, effective, and quick way to sharpen knives without getting your hands dirty. Traditional manual methods can work well, but an electric sharpener is sure to save you time; likewise, these instruments are built with precision in mind, leaving the guesswork out of the process of ensuring correct angles.
How it works
Popular electric sharpeners consist of three slots, or sharpening areas, where a knife will be inserted. Each slot will sharpen the knife at a different angle, or bevel.
The first area typically creates a 15 degree angle on the knife, the next allows a slightly steeper, sloped angle (for a double-beveled edge), and the last creates another bevel at a 25 degree angle. High-quality electric sharpeners should hone (polish) the sharpened edge of the knife.
Know when to use what
In general, it isn't necessary to use all 3 sharpening areas each time. The first area, in fact, will hardly be used at all, due to its extreme angle (which has the ability to strip a lot of the metal away). Only use this area if you have an abnormally dull blade or a blade with a nick in it.
The second area (or stage two) is used on dull, but not damaged, knives. You shouldn't have to use this stage very much either, but you will use it more often than the first area.
The third area is used to re-sharpen blades that already have a nice shape to them, creating the finest blade. This is also the stage used to sharpen serrated knives. Never use the first two areas on a serrated knife.
Turn it on
Once you have determined what knife and what in stage you plan to sharpen, all you have to do is turn the machine on and insert the blade into the crevice 1 to 3 times per side. That's it! Viola, you're done!
A word of caution
Electric knife sharpeners have the capability of removing a lot of metal from the knife quickly. In fact, they can be downright aggressive. Make sure that you use a sharpener that has a slow grinding method and grinds in several stages. If, for example, you attempt to use step 1 on your knives regularly, you'll no doubt strip the metal down to nothing. Also, using a poor quality electric sharpener can ruin your knives.
More information on knife sharpeners