If it's mainly for practice, why not just cut it off? An easy way would be if you have a serger that could cut and secure the edge at the same time. Then just find some more fabric that is wider. If it was me and I was sewing to the back to fold over to the front, I would use 3" wide that way I could use a pretty decorative stitch and it would hopefully miss stitching on the binding on the backside. Helps also if you have a busy print on the backing fabric.
Have you watched any of the binding videos for making a mitered corner? Lots of them on you tube and also some good ones at Missouri Star Quilt Company.
Here's Jenny's binding tutorial:
http://www.youtube.com/watch?v=-GVA0...IzuAw&index=69