The proper way to sharpen a knife is to stroke the blade at a 20-degree angle on a damp sharpening stone. Although an electric sharpener is also an option, it takes off more material from the blade, throwing the knife off balance after several uses.
To sharpen a knife with a sharpening stone, begin by soaking your water stone for at least 45 minutes to prevent catching on the blade. Place a dish towel on a cutting board, and place the stone on top. With the heel of the knife at the far edge of the stone, hold the blade with both hands at a 20-degree angle before dragging the edge of the blade down the length of the stone toward you. At the same time, the point of contact should move toward the tip of the knife. Maintain even pressure, and continue dampening the stone as needed.
Repeat the process until the stone holds a film of water with silt, around 30 to 40 strokes. If the knife has a double-edged blade, repeat the process for the other side. If the stone has formed grooves, use a low-grit stone fixer to smooth it out. Finally, test the blade to ensure it has achieved your desired sharpness.