Hi to all,
The following tutorial shows the proper way to fasten two loops together.
You need to have two lines with loops in the ends. This is useful for connecting a leader to a fly line or a tippet to a leader. A Perfection Loop, a Surgeon Loop or a Non-Slip Mono knot can be used. The loops shown in the photos are large for the sake of the demonstration. When fastening a tippet to a leader the loops should be as small as possible.
Place one loop over the other loop.
Pinch the two loops together between your thumb and forefinger.
Take the End of the line you placed over the other loop and put it through the loop in the other line.
Grasp the end of the line you put through the loop and pull all the slack through the loop.
The two loops will inter-lock like shown in this picture.
Grasp both lines and pull the knot tight.