Fishing knots don't have to be a roadblock on your way to fly-fishing Nirvana. Don't be put off by 100-page knot books or long lists of knot illustrations and videos on-line. You don't need to know all those knots.
You only need to know a few basic knots to get started fly fishing in fresh water. Practice them at home before you go fishing so you don't find yourself wondering how to tie on a tippet just as the trout begin to rise and the sunlight starts to fade.
When you are comfortable with the basic knots, you can add more knots to your repertoire—knots that serve specific, specialized purposes such as a loop knot to allow your fly to move more freely in the water; the George Harvey knot for hooks with down-turned eyes; or special saltwater knots for heavy monofilament.
Right now, you just need to know how to attach your fly (fisherman's knot), how to connect two pieces of monofilament so you can add a tippet section to the end of your leader (blood knot), and how to tie a tube nail knot to attach a leader to your fly line in the event your fly line does not have a looped end. It's also helpful to know how to join two loops together.
Strong knots. When fly fishers talk about strong knots they are mostly referring to the final knot connecting the fly to the tippet. This is where strength is most critical because the diameter of the line is at its thinnest.
The most popular knot to attach the fly to tippet is the improved clinch knot. Although it is an easy knot to tie, and many fish have been caught with it, the improved clinch knot is weaker than many
other knots. The fisherman's knot—also called the Eugene bend, Pitzen, 16-20, Heiliger, and other names—is stronger and works to connect any fly to the tippet.
Lubricate the knot with saliva or fly floatant before you pull it snug. George Anderson—owner of George Anderson's Yellowstone Angler in Livingston, Montana—uses lip balm before he ties two monofilament sections together. He forms the knot, then uses his lips to lubricate the fly before he pulls it tight.
If you pull a knot tight and there are curls, abrasions, or other deformities in the monofilament caused by the heat and friction of closing the knot, you should cut it off and try again.
Deformities show you that the monofilament has been significantly weakened, and although the knot itself may not break, the line will break where you have damaged it.
Pull the knot snug and make sure it is seated and tightened correctly. Most knots require you to hold the tag end so it doesn't slide out when you tighten the knot.
Clip the tag end of the monofilament only after the knot is completely tightened and seated correctly. Clip it short and neat, but do not clip it so close to the knot that the tag can slip through completely, or so close that you risk nipping the knot itself. It's okay to leave a short tag no longer than the diameter of the hook eye, and your knot is probably stronger as a result.
Retie your knot after you catch a large or toothy fish, snag trees on the backcast, or drag your line on the bottom. Regularly inspect your entire leader for nicks and abrasions. If you don't, you may regret it when you lose the fish of a lifetime. You should always be thinking that the next fish could be "the one" and prepare accordingly.