Non-Waxed dental floss works best for me. Here's what I do:
Double the dental floss, wrap it around the string above the peep and then thread it into itself through the loop. Repeat 5-6 times. Then seperate the two ends of floss and carefully wrap down your split bow string (around the peep) in a spiral pattern. I prefer to wrap them 3 times above the peep and 3 below. Rejoin the two sides of floss and repeat the same first step you did above the string 5-6 more times. Remember to slide it together tightly after each wrap. Once this is finished seperate the two ends one more time, wrap them around your bow string in opposite directions and tie them in a square knot 3 times. Trim the excess and burn the ends.