Unfortunately, the arrays of modern whetstone can be bewildering to the inexperienced sharpeners that so often times many of them end up with a crap or wrong decision on stone type for their utensils. The most difficult to determine is whether the whetstone is fake or fabricated with low quality of materials. To avoid this you can only go for the reliable brand of a whetstone.
To take off the fine scratches and burrs left by coarser stones, and to polish the surface, you can use stones starting at around 2000 grit. There is theoretically no upper limit, but stones above about 10000 grit achieve practically no measurable improvement in the edge. It is also interesting to note that above 8000 grit, there is no Japanese measurement standard. For stones labelled as having a finer grit, you simply have to take the manufacturer's word for it.
With its premium series Select II, the whetstone manufacturer Sigma Power Corporation from Tokyo addresses users of high-alloy steels such as HSS. These stones, too, are obviously intended to engender a grinding experience similar to that of natural stones. The special production process is expensive, but the Sigma Select II probably has no equal when it comes to demolishing steel.
Ceramic sharpening stones were the early replacement for natural stones. Unfortunately there are huge differences in the quality of ceramic stones so be wary. Some are extremely soft and dish out very quickly and at the other end of the spectrum some are so hard they tend to glaze over in a hurry. Ceramic stones need a good soaking for about 10 or more minutes to saturate the pores of the stone prior to use. As all knife steels are different we tend to find that ceramic stones tend to work better with some knives over others. There are no hard and fast rules but we like ceramic for Ao-ko and single edged knives. The Kaiden Ceramic stones are the fastest cutting Japanese stones in Australia and are recommended for advanced users.

Finally, when you learn how to sharpen a pocket knife becomes reality, you'll ultimately see the difference in your blade. Every sportsman and kitchen guru should learn how to sharpen a pocket-knife the proper way without "nicking it" or "shaving the edges" off too much you end up with a short and stout blade. Consequently, selecting the proper pocket-knife sharpener is important so learning the in's and out's of how to sharpen a pocket-knife before and after using it is all in the practice as well as in the sharpener itself.
When the block is intended for installation on a bench it is called a bench stone. Small, portable stones (commonly made of bonded abrasive) are called pocket stones. Being smaller, they are more portable than bench stones but present difficulty in maintaining a consistent angle and pressure when drawing the stone along larger blades. However, they still can form a good edge. Frequently, fine grained pocket stones are used for honing, especially "in the field". Despite being a homophone with wet in most dialects of modern English, whetstones do not need to be lubricated with oil or water, although it is very common to do so. Lubrication aids the cutting action and carries swarf away.
Again, burr formation is critical to success and if you are using a 1,000 grit stone on a dull knife, you may be there for a while but it will form. If you are grinding on one side for more than 3-4 minutes, flip the knife and work the opposite side, always feeling for a burr with your thumb on the opposite side to which you are working on. Remember, the fatigued metal is being forced down the blade towards the edge of the edge by your actions and the abrasive properties of the stone.
A single stone of 120 grit and a combination stone of 1000 and 3000 grits come along with a stone holder all for a price of less than many other individual stones. The stones are 6 7/8" long and 2 1/8" wide. A flattening stone of some kind would be needed, but with economical options available in those, the overall price of this kit would still be low. This entry level set is a good budget minded option.
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.
Now you may wonder, if a finer stone produces a better cutting edge why do I need a coarse stone at all? The answer is that finer stones work much more slowly than coarse ones. The amount of metal a fine stone removes with each pass is much less than what a coarse stone removes. If you have an edge with a good shape to it from a coarse stone, this is not a problem because the fine stone doesn’t have to remove much metal to improve the edge. If the edge is dull, it will take many times longer to reshape it with a fine stone than it would with a coarse one.