The must have fly fishing accessories & tools you need when fly fishing. First you need a good pair of line cutters (nippers) Try to find something in a fluro colour and non reflective, it is advisable to have them attached to a lanyard on your vest. You will also need a quality set of fly fishing forceps, I like the scissor forceps as they have the scissor that is usefull for trimming flies. Most scissor forceps have a screwdriver head in the handle that is handy for streamside reel repairs. so three tools in one. Some sort of tippet organiser that can be attached to your fly fishing vest saves you rabbiting through your vest looking for the right tippet. You will also need to carry floatant strike indicators and spare leaders. The choice of what you can carry is endless try to keep it to a minimum, I like to go through my fly fishing vest at the beginning of each season to reveue wether I can iliminate some things to cut down on weight. It's suprising how quickly the weight in your fly fishing vest increases.
A good way to organise your fly boxs is to store all your nymphs, dry flies and streamers in seperate boxs as you are fly tying. If done when fly tying they are immidiatly organised and not floating around in draws fly cups etc:.
Accesories fo fly rods like a rod clip or
a carrier for spare fly rods can also be useful depending on the type of fly fishing you are doing.
Reels fly reels fly