I don’t know how everyone else is doing it, but I’ve resorted to using a Paper sharpening wheel Which also comes with The strop wheel. I basically practiced on an old head or two until I get the hang of it, now when I’m done sharpening those heads they’re devastatingly sharp, and my blood trails show it. I used to use the file techniques and never had even close to the same results. I have hit high double lung where the blood trail was hard to follow because it was like a sprinkler out both sides, It would get confusing on which way the deer was actually going there was so much blood. A few years ago I hit one high in the loin and had no trouble tracking it almost half mile, it just took a bit to pick up the initial blood trail And I ended up catching up to it and seeing it was not going to die from that wound so far as I could tell. The first many deer I shot with grizzlies had poor blood trails but they were also not nearly as sharp as I get them now. I shot a deer with a four blade stinger the other day double bevel right through the heart and it was not an easy blood trail to follow, not really easy and not really hard. So I don’t know I think sharpness is the biggest factor, and I’ve had such great luck with grizzlies I just keep using them unless I need some thing where a grizzly won’t fit the weight or whatever exactly I’m looking for at the time or I don’t have any sharp ones laying around.