I found a great way to experiment with a quilt pattern!
Make a picture of your quilt and print it in color full page.
Then use transparents (that were used for overheadprojectors) and lay one on your picture. Take a Sharpie or a dvd-marker and draw on the transparent. This way you can try several patterns.
Some use transparents directly on their quilt. I wouldn't try that, as Sharpie is hard to remove from fabric!
Have fun quilting!