You have to be willing to cut chunks off and discard them. If you go at it like a paper pieced block it is easier. Start with a piece in the center of your backing and just start adding, flipping, pressing and adding. Clip off only when you know it is sewn down on all sides or you may be sorry and have to patch an area. It is ok to add by hand too. There are some good books, my favorite is a small hard cover spiral bound by J. Marsha Michler Crazy Quilting the Complete Guide. She includes 10 ways to patch a crazy quilt, 100 embroidery stitches, embellishments and loads of beautiful color photos for inspiration.