Steps:
1. Following the diagrams, fold paper as shown in steps #1 through #5. 
2. Insert a 4” x 6” card, then fold the outside points toward the center, to hold the card in place, as shown in #6. 
3. Fold the points back where the flaps intersect as shown in #7.
4. Open the point with fingertips or bone folder and squash flat for a diamond shape, as shown in #8.
5. Fold the top point down, insert the tip into the diamond shape to hold the envelope closed, as shown in #9.
6. Embellish with rubberstamps, stickers.

Click for larger pattern view.