If you don't have a knife sharpening kit and you're in between taking knives down to the cutlery store to get sharpened, you can put a little bite back into your knife with a coffee mug.
Photo by Rhett Maxwell.
Over a the site DIYLife they highlight a way to sharpen the edge of a knife using a coffee mug:
It's true, the bottom of most ceramic coffee mugs have a flat, unglazed ring that is the perfect surface for giving that dull knife a quick sharpening. Just run the blade across the bottom of the mug at a 45-degree angle, working from the butt up near the knife's handle to the tip. Slide the blade downward in one direction, keeping your fingers out of the way as you work.
We'd definitely stress that this isn't a perfect solution for continually sharpening your knives, but if you need to clean up the edge and buy yourself some more time before a proper sharpening, it'll do in a pinch.
Check out the full article at the link below for additional information and tips on sharpening other kitchen implements. If you have a knife sharpening tip or trick to share, let's hear about it in the comments.
Sharpen Dull Knives (Scissors and Can Openers Too!) [DIYLife via TipNut]