The best way to keep your knives sharp is to use a Japanese whetstone.
The stones are double sided and graded and designed to be used on a range of blades from kitchen knives to scissors. Its easy to do and hugely satisfying. Soak the stone for 5-10 minutes before running the blade up and down the length of the stone.
Keep the blade at a slight angle, ensuring the edge is always in contact with the stone. Most importantly work each side the same number of times one section at a time until the whole blade has been sharpened. Check out online videos for a proper demonstration.