Then fold in the two side pieces, again using the iron if they don't stay.
You then need to bring the top down, to make an envelope.
Open it up, and you will see the area you have to put your message in.
Cut a piece of fabric to size, I went for a textured piece, looks a little like old paper. You can then decide on your Valentine's message I went for a simple 'I heart U', using stitching and a fabric heart.
If you want you can added a little 'label' to the front of the 'envelope' I stitched 'BE MINE' on to a piece of white fabric, and trimmed the edges with pinking shears.
Using fabric glue, glue the 'lable' to the front and the message on the reverse, once it has dried you can place it for your loved on to find!
I'm linking to some of the amazing blogs in the side bar.