Nail Knot

The Nail Knot is the most commonly used knot for attaching leaders and leader butt to fly line. This knot is not recommended for big fish as the knot depends on the outer coating of the fly line for strength.

• Lay a nail or hollow tube against the end of your fly line. Set the
  butt section of your leader against the line and the tube or nail.
  Leave an extra 6" to 10" of tag end to your leader to tie the knot.

• Hold all 3 pieces together with your left thumb and forefinger
  and make 6 to 8 wraps (close together) around the leader, line
  and nail; working from left to right.

• Pass the tag end through the tube or space made by the nail
  and remove the tube or nail. Pull the tag end to snug up the coils.

• Pull both ends of the leader and fly line simultaneously to
  seat the knot firmly onto the fly line. Trim the tag end close
  to the knot.