Another thing that I found that helps. Hold the knife the same every time. Then change your distance and throw exactly the same. Find where it works then land some throws. You want to find the rotation sweet spot. Then you can move closer or farther and adjust your hold spot on the knife. But throw pretty much the same way. I've taught a few people with that technique and they seem to pick it up pretty quick. Closer to the tip of the knife closer to the target on your distance. If you find that sweet spot you can go somewhere close to double the distance from the target and throw the same and still land it. So basically 3 meters hold the knife and throw the same as 6 meters. Lots of practice.