There are ton of fishing hook files on the market. Honestly, I’ve used a lot of them, and the best ones have longer sharpening stones to give you a longer stroke. Another helpful feature on a good hook file is groves in the stone. The groves in the file make it easier for sharpening hooks. Diamond stones are the best because they will sharpen anything knives included. Also, you need to consider grit count on your stone. A lower grit count for 100 – 200 is rougher and will grind the edge more, but won’t get it as sharp. A higher end grit around 800 – 1000 will give you a nice fine edge.