If you are talking about a cape... here you are...
My method's weird and not for everybody, involving literally just making a flat sheet of green modeling putty, then fold and prod it it to look like a cape. It's a pain and not the way I do things now.
THe simpler way, and the way I wish I had done my previous capes, is that you use a bit of wire as your framework to put a sheet of green stuff on. Don't make it straight, but put some subtle waves into it, it makes it look better. Let this cure. Then you put rolls of green stuff on to suggest billows and folds, blending it into the cured sheet. And you have cape.
