There are tons of accessories available to fly anglers, but in my eyes only a small number of them can be considered critical. From floatant to pliers, forgetting one of these ultra-important items can really disrupt a fishing day, or in the worse-case scenario, ruin it altogether. In the title I eluded to a certain item that can definitely be worth its weight in gold, and that is a simple hook sharpener. It's funny because despite me being an obsessed angler for about 25 years now, I didn't consistently carry a hook sharpener until just a few years ago. Similarly, I have a feeling many anglers out there don't carry one, either. Just like my cell phone, I wonder how the heck I ever lived so long without one!
You may think a hook sharpener is not such a big deal, but hooks can become dull many different ways. Depending on the fishing you do, this can be a constant problem. As I said, I used to be hard-headed about carrying one and totally disregarded it. I felt like my hooks were always at least adequately "sharp enough" and if they ever went too far downhill I could just tie on a new offering with a fresh hook. Thankfully, I've since overcome this thought process. How can a fly's hook become dulled?
Snags- When your hook snags onto something hard like a rock, stump, or chunk of concrete, that's a surefire way to ruin that nice sharp point. Not only can it become dulled, but the tip of the hook point can actually become bent—and that won't catch you ANY fish!
Casting- Unless you're roll casting, the typical fly cast involves a back and forth motion of line in the air known as false casting. While casting in a spot that's not totally free of obstacles, it can be common for your fly to occasionally (or constantly) smack or briefly tick against something. Even if you make just one sloppy back cast where your fly contacts that sloping gravel bar behind you, that can be enough to dull a hook point.
Dragging/drifting over rocks- If your fly is being pulled or drifted along a rocky bottom, make it a habit to check the hook point consistently throughout the day. The constant bottom contact can take its toll over time, but that can be reversed with a few swipes of a hook sharpener here and there.
Rust- Fly hooks can become rusty which can hamper their ability to pierce a fish's mouth. Bust out your sharpener and get a crusty hook back in to tip-top shape.
The hook sharpener I carry for much of my fishing is a small and low-profile one called the EZE Lap hook sharpener. Modeled after a pen, it has a protective cap with a clip on the outside which can be handy for hooking onto something like clothing or a bag. Take the cap off and there's an approximately 2-inch diamond surface that's smooth on one side and grooved on the other to make sharpening a hook point just a tad easier.
I don't use any secret methods to sharpen my hooks. I find that just a few strokes of the sharpener around the point usually gets it done. I've seen folks sharpen hooks by swiping the hook along the surface both in the direction of the hook point and going away from it. I've always done the latter, and I generally do an even amount of strokes on all sides to keep things uniform. Don't saw the sharpener back and forth—swipe in one direction only.