This video teaches you how to tie a blood knot which is used to tie two lines together in a very strong knot. Fly fisherman use this knot for making their own fly leaders. Wrap the right line around the left line five times. Take the end of the right line and put it in between the left wrapped line and the back of the right line. Wrap the left line around the right line five times, repeating the earlier procedure. Make sure you bring the line up through the hole that is created in front of the wrappings so that the two opposite lines are going different directions. Pull the lines tightly and your blood knot is complete.