Whether you buy expensive knives or cheap knives, they all get dull with use. You can have your knives serviced by a professional, or you can learn how to sharpen your knives yourself. A word of caution: learning to sharpen your knives takes time and practice; don't begin by trying to sharpen your best knives on your own as you could damage the blades.

Although your knives may seem sharp, a practical test can tell you whether your knives need to be sharpened. Slice a ripe tomato – if you can slice the tomato easily, you're knife is sharp; if the tomato squishes down and is difficult to slice, then it is time to add your knife to the ‘to-be-sharpened' drawer.

Knife blades are essentially tiny saws, complete with teeth. With use, these teeth get worn, bent or twisted. Knives made of harder metal don't get dull as often as those made of soft metal, but when they do get dull, they are more difficult to sharpen. It is necessary to find a substance harder than what your knife is made of to sharpen that knife. Metal sharpeners called steels are often used by professionals like butchers, but for most people who own stainless steel knives, a ceramic sharpener may be a better choice.

Using a Ceramic Sharpener to Sharpen Your Knives:

• Begin by placing the heel of your knife blade at the tip of the sharpener and then sliding the entire length of the blade down the sharpener. Keep the pressure and angle constant; you should feel the abrasion between the cutting edge and the sharpener.

• Plan your stroke so that you will finish with the point of the knife's blade near the base of the ceramic sharpener. Repeat this move on the other side of the sharpener to sharpen the other side of your knife.

Steel Sharpeners:

• If you choose to use a steel sharpener rather than a ceramic one, begin with the heel of the blade at the base of the sharpener (rather than at the tip as with the ceramic sharpener) and work your hands away from each other while maintaining the contact between the knife blade and the sharpener at an angle of 25 degrees.

Depending on how often you use your knives, they will require periodic grinding to create a new cutting edge. If you have a sanding wheel or a large grinder with stones of varying coarseness, you can carve a new edge on your knives, but if you lack this equipment, skill or confidence, it may be a good idea to have a professional handle the grinding as it could damage your knives and possibly your fingers.