I use vinyl or thin leather like stuff to do it, SUperglued in place above the joint to hide it so it all looks like one piece. To get the wrinkled look I just pull it tight as I glue it down. You can kind of see it on the Flash in this pic, the seam still shows, usually a couple more coats of paint will take care of that.

Tomorrow is the most important thing in life. Comes into us at midnight very clean. It's perfect when it arrives and it puts itself in our hands. It hopes we've learned something from yesterday.
-John Wayne