after i tie my loop i take some serving string and tie a small knot inside of loop top and bottom .That way it cant move,and if you ever have to take it off for any reason you can retie it in the same exact spot! As every one has stated burning the ends and flatting them will keep them from pulling through.Hope that helps.

Sorry, but I find if I have the loops tied on the same side the string rotates. If tied on opposite sides they even each other out.