I hand drew and cut a heart template and traced it onto the vellum. Once that was cut, I ran it through my Xyron. I find this to be the easiest way to adhere vellum and not show the adhesive. I adhered the vellum heart to the turquoise card stock and hand cut around it to give it just a bit of an outline. I used foam tape to adhere it to the card.
This card was an odd size measuring about 5"x5.5" which meant that it didn't fit into a standard sized envelope. My solution was to take an envelope that was 5.25"x7.25" and cut it down a bit. I sealed it shut and formed a new flap at the side. I then attached two hearts to the front of the envelope and wrote their names on one of them. Turned out beautiful!
I found some purple paper in my stash and also some vellum with gold flowers. I ran that vellum through the Xyron to attach it to the purple paper. The sheer ribbon was tied around this piece and attached with foam tape to a standard sized cream colored card.
The heart was cut from cream card stock and sponged with brown ink and the small 'crystals' attached to the side, then onto the card with foam tape.