Yeah, I do it like DEEZLIN, I have a slider above and below the peep.
Being flat, the dental floss will end up being tighter and harder to slide than round serving thread. Sometimes thats good, sometimes thats bad.
With floss, I tie overhand knotts... one on one side then the next on the opposite side etc. about 3/16" long.
With round serving thread, I fold the thread in half, take the "U" shaped end and stick it about 2" past the string, reach through the loop and grab the tag end from the other side of the string and pull it through the loop and sinch it tight on the string. Repeat for about 3/16" again and finish it with a square knott. You'll find this method ten times faster than the opposing overhand knott method most poeple use.