How to sharpen your pocket knife with a diamond sharpening stone. File knife with a metal file first. Push away from the cutting edge. Remember not to over sharpen the knife. You can use an oil stone or a diamond stone. Wet the stone surface. Push gently with the knife against the stone, making many light strokes on each side. Check periodically to see where you need to even out the blade. Wipe the knife and the stone clean with a cloth. Use Goo Gone to clean knife blade. Use canned air to clean handle of knife. Oil knife with 3-in-One oil in folding mechanisms. Wipe away excess oil and place knife upside down allowing remaining oil to drain. Learn how to sharpen and maintain your pocket knife using simple tools.