Here is the simplest birthday party invitation I have every made. It is a simple hills and valley fold card. I used the CTMH retired Super Hero Paper Pack and the retired Super Powers Stamp set. So if you have a little super hero like mine this would be a great invitation to try. You simply cut your base 5.5 x 10 inches and score at 1.5,3,5, and 7 inches. Then proceed to fold it making hills and valleys. Here's how mine turned out.