I have never made one but I did a lot of research because I was planning to . . . (lol!!)
Most advice I found said that they attach the bows to a plain pin back so it can be removed prior to washing. You can purchase them at any craft store. I have also seen where people get the sew on snaps and put one on the shirt and the other on the bow.
The advice I found for attaching the ribbon to the tee is that it needs to be sewn on. You can either sew it all the way around or take your seam ripper and open up the sides, tuck the ribbon in, and resew the seam.
Hope that helps. I really want to get it in gear and make some myself. Got all the info ~ just need to get it in gear.