Rigging for a day of fly fishing is a really crucial time that shouldn't be taken lightly.
I consider myself a super careful and methodical person, but like any other human, I sometimes goof up or overlook something when I really shouldn't. This includes when preparing for a day on the water. The vast majority of the time, I rig carefully and triple check that everything is up to snuff. However, if for some reason I'm distracted, rushed, or just having one of those days where I'm just not quite "with it," errors can and do happen.
Some mistakes can funny—like when a ferrule isn't on tight enough and half the rod goes cartwheeling out into the water during a cast. On the flip side, other errors or oversights can lead to a long day of frustration or a blown opportunity at a big fish. This is why preparation before the trip is so important. Preparation deserves your full concentration and goes far beyond just freshening up the leader and tying on a fly.
Besides more "standard" checks like looking over your leader for abrasions, making sure the ferrules are lined up, proper knot tying, and tightening down the reel to the rod, here are 4 other things that may be overlooked when setting up your tackle:
Line Condition: Wouldn't it be nice if fly line was maintenance-free? No matter how often you fish, line will eventually get dirty and/or dried out. Of course you can still use it in this condition, but that can be supremely annoying. Fly line that isn't clean and smooth won't flow through your guides as well and built-up gunk can even cause a floating line to start sinking. After a good cleaning, however, the difference in performance can literally be night and day! Like me, those of you who spend a lot of time fishing from the shoreline probably notice that a fly line can get dirty pretty quickly since it's getting stepped on and dragged through stuff like dirt, sand, and mud. Check your lines often and make note of their performance every trip. If on the last trip a line was starting to lose some performance, tackle the problem sooner rather than later. Whether you need to clean lines once a month or once a season, keeping them fresh and smooth will result in a more enjoyable and productive day.
Tag Ends: After a knot is complete, I see some anglers clipping their tag ends so short that they basically disappear. No matter how good I moisten a knot and pull the heck out of it, I always always always leave a bit of a visible tag end. To me it's just added insurance. I realize a knot looks really clean and flows through guides smoothly with the tag end gone, but I've always found that leaving a tiny tag end behind doesn't make a difference in regards to overall fishability. The fish don't care, and it allows for a tiny bit of "just in case" slippage whether fighting a fish or pulling hard on a snag.
Hook Check: Before tying on a fly that's been previously used, always check the hook. While a quick inspection may seem like all is okay, concentrate really closely at the very tip to make sure it's not broken off, rolled over, or substantially dulled. Sometimes in low light, I'll even carefully run my finger along the hook (going away from the point rather than towards it so I don't get poked) to feel for a tip that's not perfectly straight. Checking hooks is one of those things that shouldn't only be done before fishing, but also during. I perform many hook inspections throughout the day, especially after every hard snag or if I hit an object behind me on the back cast.
Skipping a Guide: Several weeks ago, I was out testing a new fly rod. After my first few casts, I felt like something just wasn't quite right, but I continued casting and retrieving anyway. A few more minutes went by and I finally noticed it....I had completely missed stringing the fly line through one of the snake guides. Duhhhh! When this happens it's usually when I'm in a rush to squeeze in a quick fishing session. It's also surprisingly easy to not notice while fishing—especially if not specifically looking for it. Maybe I need to wear my glasses more often? Typically, when my rigging is more relaxed, I'll string up the rod then double check that I've threaded all the guides properly.