I love my punches and I am always trying to learn and find uses for my punches. At a crop I learned how to use a corner punch to make a medallion-like shape. It will have to wait, since I don't own any corner punch, but I thought of a way to use a scalloped circle punch as a corner punch.
You will need a scalloped circle punch and a rectangular piece of paper. My punch is a 5cm (2 inch) Woodware punch.
Turn the punch upside down, and slide one corner inside the punch.
Repeat for each corner and you'll get this: