Demonstrations by Rick Reed
Bend the heavier of the two lines in a loop, and pass the lighter line through the loop. Wrap the lighter line around both strands of the loop 10 to 15 times, and pass through the top loop, making sure the tag exits the loop on the same side it entered. Slowly tighten the knot from both sides.
Lay the lines parallel and facing in opposite directions and cross the end of one over the other. Wrap this line three or four times around the other and place the end of this line in the crotch or the V formed by the two lines. Do the same with the other line, being sure to pass the end through the loop in the opposite direction to the first line. Slowly pull on the standing ends of the lines to draw the knot together. When the knot is formed, lubricate with saliva and pull the knot up tight. Trim the tag ends off so that they don't catch in the rod guides.
Overlap the two lines with an area of about 6 inches. Form a loop with the tag end of one line. Make three turns with the tag end over the two lines and back through the loop you created. Snug up by pulling the tag end. You have just completed the first Uni Knot. Repeat steps 1, 2 and 3 with the opposite line you used for the first Uni Knot. Wet line on and between the two knots and tighten by pulling the lines on each side of the knot in opposite directions simultaneously. Pull tight and trim the tag ends close to the coil.