Susan Carlson also does great collage quilts. You can find her method on her website
www.susancarlson.com. I have been fortunate to take a class with her and she does amazing work. You might have seen her salt water crocodile: Crocodylus Smylus aka Stevie. Here is a time lapse of the quilt
https://www.youtube.com/watch?v=FtTUOM8POoQ