Pencil in a light line on the back and align the blade of the scissors with the line. Also watch the tip of the scissors and keep it on the line. Don't cut all the way to the end of the scissors. Instead, cut partway and then reposition the paper, matching it up with the pattern on the scissors so you get a continuous design. I learned that by reading Joy of Scrapbooking, by Lisa Bearnson and Gayle Humpherys.