There are so many great reference materials already out there. I watched countless hours of videos on YouTube before even attempting to sharpen. To name a few youtube accounts I like: Outdoor55, Knifewear, and Ivanyuka-Japan. I don’t think there is a lot I can contribute beyond the wisdom they have freely shared already. So, instead, I will focus on the things I struggled with on my knife sharpening and maintenance journey.
The #1 thing I tell all my friends and customers is to practice, practice, practice. This is with a caveat though: practice on a cheap knife, or a knife you don’t care about if you mess up. Most people who are upgrading their knives are most likely coming from generic knife block sets or grocery store knives. These are the perfect knives to practice your technique on. You do NOT want to buy a cool, shiny new knife only to scuff it up by accident. The reason you want to practice on a “beater” knife is because you want to make sure that when you mess up (you will, and it's okay!), it is on a knife you don’t care much about.
One of the first mistakes I realized I was making was not keeping the angle of the knife. I wasn’t holding the knife in a way that was conducive to keeping the same angle while running the knife across my whetstone from start to finish. Two things can happen when you do this: you create an uneven cutting edge, and you can scuff up your knife pretty badly. The hand that's bearing most of the weight of the knife should be locked at the wrist, this will be the most important change to keep the angle consistent. When you slide the knife up and down, you should be using your elbows/shoulders and not your wrists. How do you learn how to keep an angle? Repetition. Repetition. Repetition.
The other big mistake I made was not making sure my stones were completely flat. Certain stones will “dish” quicker than others, meaning that there will be low spots formed that form because we don’t wear down the whetstone evenly while we sharpen. If you do not flatten the whetstone, it will create an uneven bevel and potentially create a cutting edge that is more brittle. It can also create situations where your knife doesn’t slide smoothly and you may end up scratching the knife or even cutting your finger by accident. If you can’t afford a good truing/flattening stone, it has been suggested to go out to your sidewalk and use that in lieu of one. I personally have not tried this, but I don't see why it wouldn't work. Just make sure the stone and the sidewalk are thoroughly soaked with water.
In a previous post, I linked to a 1000 grit Shapton glass whetstone. For those who prefer a thicker stone, I will be linking to a Suehiro 1000 grit whetstone. This stone is quite thick, at almost 2 inches thick. This means that it will last a long time. Suehiro is a trusted brand among knife sharpeners.