You don't want to slice your finger open from slipping on a dull kitchen knife, but for whatever reason maybe you also don't have a whetstone or honing steel. The solution here would make MacGyver proud: flip a porcelain dinner plate over and use the bottom rim to hone your knife.
Take your kitchen knife, point it at the rim of your plate at a 20-degree angle, and slide it along the entire length of the blade in one direction. Do this several times and repeat on both sides. Remember to rinse the blade in the sink before you use it. Done!
The bottoms of dishware, including coffee mugs and bowls, are sturdy enough to be a quick and dirty solution to your dull knife, that's all. We wouldn't recommend this as a full-on replacement for a proper honing tool or using this with a really fancy knife. And for the love of having your fingers intact, invest in a sharpener or honing steel after trying this.
How to Sharpen Your Knife Without a Sharpener [Reactions]