I had a problem with the first Styrofoam/foam stuff I used. It was the crumbly soft kind and when I tried to tape it down so it would not stay put! Luckily we had a small Styrofoam ball left over from The Bluebird of Happiness project that I cut in half and taped down. (I wish I would have thought to use play dough like Joann at Ten kids and a Dog!) Eventually I added some cotton balls to make it look like clouds.
So, after getting that worked out I had Indy stick one end of a pipe cleaner in one side then thread on at least 6 beads the same color of the pipe cleaner then stick it in the other side. After he was done I transfered the whole thing to blue paper so we could keep it and admire it forever. ;)
This was another Rainbow project we did last week. It's called "Catch a Rainbow". You can get the details here.