I make them! Do a search here on cheer bows...they only use pony-o's so that might help.
What I do is make the first two loops of a boutique (or twisted) bow, sew the loops together in the middle, letting the tails hang down at the bottom. Pinch the middle accordian-style, wrap the string around it and tie off in the back. Then I use a piece of 3/8th for the center. I put the pony-o on the back of the bow and cover it with the end of my 3/8 piece and glue this end to the bow back. I wrap the 3/8 around the center of the bow in the front and glue the other end on the back so the pony-o is covered (and so is my sewing).
I just started doing these, so I don't know if it's the best way, but I tested one out with my daughter and it stayed in (and stayed put) all day
I hope this was easy to understand! I can take some pictures for you if it would help!!!!