I might as well make use of this blog for a bit of blatant promotion for my business, so I'm going to occasionally feature items that I find really useful. A good hook hone is something I learned the value of when I was doing a lot of lure fishing. It's invaluable when fishing rocky rivers for barbel and chub too. That's why all my tackle boxes contain an Eze Lap Diamond Hook File. They are ideal for single hooks larger than a size 12 (below that I just tie on a new one when the point has gone or turned over) and also for trebles below a 2.
Despite what people might tell you chemically sharpened points can be touched up with a file. The trick is knowing how to do it. Don't go mad. Light strokes going towards the point, working your way around the circumference of the point are what is required. I use the groove of the Eze Lap to start with, then the flat side to finish the job off. The groove is also useful for straightening a point that has turned over.
I described the hook sharpening process for lure trebles in an article on dlst.co.uk and it applies just the same for singles and with a diamond file. I'll repeat the important stuff here.
Treat a hook point as having six faces when viewed from the front of the point and you are getting the picture. File each face to get a really sharp point. One that is 'sticky sharp' and will catch as soon as it touches something. I test hook points on the ball of my thumb. Others use a thumbnail. Take your pick.
Always file towards the point of the hook. Never use a back-and-forth motion. File the sides of the point first (A &B), then the outside faces (C & D), and finally the faces on the inside of the hook where the barb is (E & F).
With curved points the inside is impossible to sharpen. So don't bother. Unless the point has been turned in it won't make any difference as sharpening the other 'faces' will suffice.