I like the dental floss in just the area where the nock goes.
The way I like to tie them is pretty easy and lasts very well.
Cut a piece of floss about 10" or so.
Lay the bow on it's side.
Then tie it in a single overhand knot around the string in the middle of the floss. Tie it so the knot is on top.
Flip the bow over and tie another overhand knot so it lays right next to the first knot but on the opposite side of the string..always tie the new knot so it's on top.
Be sure to tie the knot the same way each time...ie right over left and under or left over right and under...just do it the same way each time.
Then flip and repeat until you like the length.
Once you get enough length of floss on the string, tie it off with a square knot.
trim the tails about 1/4"-3/8" long and melt them down with a lighter. Kinda press the ends in a bit while still hot and soft.
Finish off the knot with a drop of super glue if you want.