Here's my example:
medallion card I followed the tutorial from a couple of weeks ago. I cut my dimensions a little different though. My CS is 3" X 3". I found this worked better for me and gave me nicer corners and believe me, I punched through a FEW before I liked the end result.....lol What I did was, made sure I had both sides of my CS evenly spaced and punched basically in the middle of my punch. Turned the CS, punched again, etc. until all 4 corners were done. Very simple.
Edited to add: I embossed the middle of the medallion with my CB and my 2" X 2" CB folder. TFL!