Let's get stoned: Whetstones
What is a whetstone?
Have you ever though what it is made of?
Modern whetstones are made of a bonded ceramic abrasive. Silicon carbide or aluminum oxide ingredients are essential in the process. It is worth pointing out that bonded this way abrasives provide a faster cutting action than natural stones
Roy Underhill would probably disagree with me. In his book The Wood Wright's Companion, he argues that stones found in a quarry or a mine can replace modern products on the market. Very possible that it is the case. I have no experience with natural stones yet.

One thing I know for sure – stones get out of shape. Since I first started the company, I used three sets of whetstones in total. Each stone is different than the other. It behaves the way it wants, depending on the bonding compound used. Cheaper stones start to lose their material while knife sharpening and can cause minor damage to the knife.
Step by step we get there
Knives and scissors can be hard to get sharpened. Curved knives, for example, cannot be sharpened on a whetstone due to the shape. Serrated knives will ruin the stone leaving marks on a perfectly flat surface. To sharpen a serrated or curved knife, I have a good set of electric grinders.

Thankfully curved knives don't live in every kitchen.

Speaking of flat stones (not the flat Earth), in my experience, flattering tools never found their use in my inventory. When I work with a new whetstone, I work from the center of the stone out, giving it the U shape. This shape helps me to be more precise with the angles that I give to each knife. Knives can be separated into groups by their cutting-edge angle. I talk about it more in the Knife Bevels article.

Essentially, you need to work with your stone, each strike gives a new shape to it, as well as to the knife. Once you learn how to focus on areas on the stone's surface, you will understand how to shape your stone the way you want and that works best for you.
Regarding the grit number, I prefer a set of whetstones in the range of 1000 to 6000-grit. In collaboration with the electrical grinders, I get the best result in return. I tried to go higher than 6000-grit, but it feels like the difference is not as significant. I leave the window open in case I find a good enough reason to sharpen knives with an 8000-grit stone or higher. I talk a little more about it in the Knife Sharpening article.
It is more about your style that you find attractive. It all comes with experience, just like everything else.