FIRST STEPS:
Start with a bit of target practice. While it may be tempting to go straight to the water, the best place to teach casting is in an open, grassy area such as a public park or backyard. Place a hula hoop, small tarp, or blanket about 20-25 feet away (this will be the target). Next, tie on a bright piece of yarn to help the new fly fisherman see the “fly’s” location while casting. Casting without a hook also helps alleviate the anxiety often encountered by the new fly fisherman at the possibility of accidentally hooking yourself.
Once your target is set up and the budding fly fisherman is ready, they can try a few gentle casts. Emphasize stopping the cast at the 10 and 2 o’clock positions, and don’t worry about letting out more lines for now. Many beginners will attempt to use their wrists to flick the rod back and forth, resulting in rapid fatigue and a lack of accuracy. Encourage them to use their forearms and maintain a straight wrist.
The most common mistake beginners make is waiting longer on the back cast, an error that will inevitably result in a tangled line. During the first few casts, ask the novice to allow the fly to drop to the ground behind them, following it with their eyes the entire time. From the ground, ask them to do the same on the forward cast, aiming for the target. Watching the fly line on both the forward and back casts will help them get a sense of how long the fly line takes to extend behind and ahead of them.
Once they get the feel of straightening the line on both the forward and reward casting motion, you can have them start attempting regular casts. They may still have trouble waiting on the back cast, so you may have to ask them to count to two or three before sending the fly forward again (the time will vary depending on the rod, fly, and technique). It is also a good idea to have them watch both the forward and back cast to help visualize how long they should wait before starting the next casting motion.
Eventually, you should move the target further away and explain how to let out a little bit of line to lengthen the cast.
Of course, a large part of fly fishing is tying (and untying!) knots. Knots can sometimes be the most challenging part. Start with a rope or piece of yarn; this will help the student visualize how the knot comes together without fumbling with the small line diameters used in fly leaders. After that, it’s time to move on to the real thing.
Now that you and your student are ready to get out on the water, it is essential to think about where to start. Pick a lake or slow-moving river where the fly will be highly visible, preferably away from any underbrush or trees that might result in a snag. It is usually best to start with dry flies since adding a nymph can exponentially increase the chance of a tangle. If you are not planning on keeping any fish, de-barb the hook. While doing so might make it more challenging to land fish, it also reduces the likelihood of injuring you or your student!