Using a cutting board when chopping prevents knife blades from dulling. Wooden cutting boards are preferable because plastic dulls blades more quickly. Wash knives in hot, soapy water. Avoid placing them loose in the sink because you are more likely to cut yourself fishing for a wet knife, and other dishes in the sink can nick or dull the blades. You can air dry stainless steel knives, but carbon steel can rust so make sure to dry these knives immediately after washing and rinsing. Storing knives in a block or sheath prevents accidents and helps maintain the blade's edge. Sharpen your knives as soon as they become dull. Dull knives don't just cut poorly, but they are more likely to slip and cause injury. You can use a simple knife sharpener through which you draw the blade several times, or you can sharpen manually by hand with a sharpening steel. When using a steel, hold the blade at an angle to the steel rod, and draw it down the length of the rod, sliding the knife so the blade passes over the rod from handle to tip. Repeat the process several times on both sides of the blade to sharpen it evenly.