There are two cards on each page so you will want to start by cutting your paper in half.
Using your needle, poke holes through the card on each of the light gray dots.
Stitch the paper as you would if you were using aida cloth. To make your stitches look more uniform half-stitch an entire row, then go back and finish each stitch. I generally stitch bottom left to upper right and then finish the “X” going from bottom right to upper left. (see images below for examples)
When you’ve finished your stitching use a bone folder to get a nice crisp fold in your card.