In addition to the clothing and your balanced outfit there are many accessories that you should have for fly fishing. Some of these accessories may seem strange, but when wading, it is necessary to have all of your gear and tools with you.
You already have your fly fishing vest with plenty of large pockets, because that is part of a fly fisherman's basic wardrobe. You might want to put a patch of sheepskin on the front of the vast where you can keep alternative flies handy. You should also have a spring-loaded retractable spool that attaches to your vest to hold a pair of nail clippers. They come in very handy for trimming knots. You might want to attach a patch of rubber for straightening leaders. Ideally, the vest should have a large back pocket to carry light rain gear. Some vests also have a ring at the back of the collar, where you can attach the net to keep it out of the way.
The choice of your fly boxes is very important. One should have large compartments where you can store dry flies without crushing their hackles. You should also have one or two smaller boxes with foam linings and metal clips. These are for holding your wet flies, nymphs, and streamers. Having a couple of small vials to hold your dry of flies after catching a fish also comes in very handy.
A spare spool for your reel, already loaded with backing and line, is a good idea to have with you. Also a few spools of monofilament leader material, a leader wallet, a sharpening stone, and a Swiss Army knife are important for the fly fisherman to have within easy reach.
Insect repellent is essential when fly fishing. The main ingredient in many insect repellents is DEET, which is an industrial solvent and can damage the varnish on your fly rod, eat away the finish on your fly line, weaken your leaders and destroy your rain gear. If you do use an insect repellent with DEET be very careful of what it touches and try to limit its use. There are many products today that do not contain that solvent.
Having a good pair of polarized sunglasses will help you to see the fish and protect your eyes from the damaging rays of the sun. It's also important to have a small pocket flashlight with a flexible neck. This can be very useful for many things including changing flies at dusk or dawn. Other useful items include a thermometer, a small container of split shot, a good knife with several blades, and a small first aid emergency kit.
Many fishermen like to take a collapsible wading staff with them while fly fishing. It helps them to keep their footing if they are wading in a heavy current or on a slippery, rocky bottom. A small cotton mesh net with a short handle comes in handy for netting your fish. If you intend to keep your catch a small canvas or woven willow basket for holding your fish will work well.
There are many other accessories available for fly fishing today. Many of the choices depend on each fisherman's personal preferences.