So I have a hole in my paper, I used a punch, you can use whatever you like to use to make holes, remember it can be a rectangle too, whatever shape your image is on. I also have TWO of my image, or two different images, is more fun of course, and thread. ANY old thread works, I think you should use a neutral color, although you see very little of it.
You will need a liner for the card. I just used copy paper, line it up without attaching it and make that same hole in it, in my case I lined up my punch and punched it out. (photo shows liner and card)
On the inside of your card attach adhesive above and below hole. I use double stick tape. (It's miracle tape I get it from http://www.stampo.com/ and I love it)
Attach the thread to the tape at the top. Squish it down pretty good. Sometimes I even sandwich it with another piece of tape.
I then glue up my one image. I just used regular old glue stick for it. You can use whatever. I put it under the string.
Then attach the other image, carefully lining it up on top. Oh make sure they both are right side up when you do it, you don't want one to be upside down!
Then attach your liner to the inside, covering all the string and all. I didn't take a picture of that, it's pretty boring, just make sure you line the hole up exactly or your spinner won't have room to spin.
Then it's done, here's views to show you how it looks:
Final card with ribbon and all. :)
PS: This is how I've always done it but it occurs to me you could assemble the string piece, with the two images, THEN attach it to the hole, that might be easier. (although I don't think so on the triple spinner card...)But don't let it confuse you, do it however you like. :)