A very large cardboard box, the box we used was big enough to surround Caleb's chair completely.
Fluffy stuff, like the stuffing for pillows
Blue spray paint
Silver spray paint
And of course, a hot glue gun
Here is the basics of how I made it:
*We used the four sides of the box, we cut off the top, bottoms and all but one folding flap. We kept one folding flap of the box in the front. We cut a half circle out of it so that it would sit around Caleb (see picture). Paint the box blue for the sky.
*I cut very basic building shapes out of poster board and then spray painted them silver.
*I used double sided sticky squares (used for scrapbooking) to attach my building shapes to the box, that gives it a more 3-D look.
*Glue some fluffy stuff for the clouds.
*We cut 2 circles out of the back of the box and stuck superman's legs through the holes to make it look like he was flying. I think we shoved some styrofoam in the legs to keep them straight and added some fluffy stuff to make them look fuller.
*The box fit all the way around Caleb's chair and we attached it with twine. We ran the twine through the box and attached it to Caleb's back rest bars.
*Because the box surrounded the wheels, Caleb couldn't push himself, so we did all the pushing that night. He was only 4 at the time so he didn't mind it.
And that's about it. Hope that helps someone!