Although there are many ways to sharpen your kitchen knives, we believe that using a sharpening stone is the absolute best way to go about it. Not only will you get the best results, you won’t assume as much risk of damaging the blade as you would using a manual or electric knife sharpener. The problem for most home cooks, however, is finding the best sharpening stone and learning how to use it. I’m not going to pretend it’s as easy as purchasing a stone and digging right in.

Therefore, the first step to choosing a whetstone is to determine your intended purpose and then choose your whetstone accordingly. For instance, when sharpening tools that do not require a fine edge, you should choose a relatively soft, coarse, stone such as a Norton Crystolon water stone. However, for sharpening tools that do require a fine edge, a somewhat harder Norton India oil stone would be a good choice. But, for sharpening hunting knives where an exceptionally fine edge is required, a Novaculite or Coticule oil stone would be the best but, most expensive, choice. So, the process of choosing the correct whetstone for any given purpose is to first determine how fast you would like for the stone to cut and how fine an edge you need, and then choose either a soft, coarse, stone or, a hard, fine, stone of the appropriate type and grit.
I can personally verify that this will get your knives very sharp. I will spare you all the gory details, but the picture is of the instructions the ER sent me home with after stopping the bleeding and patching me up. I have to say, that’s not what I had in mind regarding “Thanksgiving tips”. So: not only will knives slide easily through spinach, but they will go through finger and fingernail like a hot knife through butter after being sharpened by this whetstone. Very clean, straight cut. Impressive, really. Just take it slow and don’t be a moron like me. 

I'm a novice knife sharpener. I've had to unlearn what my grandpa taught me in order to use these. So far, I've had decent but mixed results. I've switched to my cheap 200/400-ish cheap tool stone from harbor freight for cutting a bevel when the blade has either been damaged or did not have a proper bevel. The 400/1000 grit stone in this kit is soft. Very soft. I have bowled it out several times. It makes keeping a steady angle difficult. But these stones at this price point are meant for learning, and for that they serve their purpose.
My Fujiwara is an exceptional cutter and a pure joy to use, as a result, the mediocre knives get a pretty good break and the dream knife gets to do the lions share of food preparation. So it gets duller faster. However, it goes without saying that superior steel will have improved edge retention but at the end of the day, knives get dull, they just do and I am very happy about that, I get to sharpen them over and over!
You need to adjust your fingers as you move the knife back and forth. Because sharpening takes place under your fingers, start with them at the tip and, as you pull the knife back toward you, release pressure completely and pause. Then, shift your fingers just a little down the blade toward the heel. This finger dance is critical and takes time getting used to.
Clamp-style sharpening tools use a clamp with several holes with predefined angles. The stone is mounted on a rod and is pulled through these holes, so that the angle remains consistent. Another system is the crock stick setup, where two sticks are put into a plastic or wooden base to form a V shape. When the knife is pulled up the V, the angle is held so long as the blade is held perpendicular to the base. Several cutlery manufacturers now offer electric knife sharpeners with multiple stages with at least one grinding stage. These electric sharpeners are typically used in the kitchen but have the ability to sharpen blades such as pocket or tactical knives. The main benefit of using an electric sharpener is speed with many models that can complete the sharpening process in one to two minutes. The disadvantage is that the sharpening angle is fixed so some specialized knives, like a Japanese style Santoku, may need additional attention to sharpen to the ideal angle.

Your task as a sharpener is to remove that fatigued metal and expose the steel underneath, the fresh strong steel and bring side A and B of the knife together at the Apex precisely, sounds easy doesn’t it? Like peeling a layer off and having a fresh start, over and over. Of course there is much more to it than this but in very basic terms, you want the abrasive properties of the water stone to abrade the fatigued metal away, like an eraser.
For the common sharpening purpose, generally, people tend to use two phases. In the first phases, they use the coarse stone to shape the edges then jump to the finer stone. In application, these of the two phases can be extended with the grit stone in between. It might be varying in the number of grits or mesh in different types of sharpening stone.
A: That depends almost entirely on how often you use them. If you are a professional chef who uses his or her knives every day then you should hone them every time you use your knives. But honing has its limits and over time your edge is going to become dull no matter what. Therefore your knives will need to be sharpened at least several times a year. Some chefs, in fact, will use a whetstone on an almost daily basis in order to ensure their knives are always razor sharp. Most of us, however, are not professional chefs and may not even touch our kitchen knives for days at a time. In that case, it’s probably a good idea to hone the edge after every couple of uses and have your knives sharpened once a year.