I knew this paper would make a great envelope. First, let me suggest that you make the envelope and then customize your card size to the actual envelope size. I learned that the hard way.
I remembered the little goody suitcase I got from the Queen & Co. trunk show. It had green Stylish Stix and pink and green pinwheels. I added some Copic RV13 to one of the Stix for my pink pinwheel, and I ran them through my Cuttlebug to flatten them. The cute border on the background paper was also made with the Envelope Punch Board.
This is a large card, so I added some paper inside. It's light enough you can write over it, but it also forms a natural barrier if you want to write less. And I had one small piece of paper left, so I used almost the entire 12x12 with very little waste.