I had metal hoop and a packet of red bias tape in a bunch of unused craft supplies so I decided to make a mobile. I cut out a mega ton of felt hearts--two for every hanging heart, so that the string is sandwiched between them. This way you can't see the heart glued onto the string. Then I also did the same thing with small mirror squares. I tied each string to the hoop, including the four strings to make the hanger, then wrapped the hoop with the bias tape. She just turned two, so she's pretty easy to please, but I think she really liked it!
I uploaded a picture of the top...basically I tied four strings to the hoop, equally spaced apart. Then I brought the four strands together and tied them in a knot. This part was slightly harder because you have to make sure that one string doesn't get pulled more than another, or else your hoop will hand all wonky! Then I brought the four strands up and tied them to a hoop.