Open your card up and it will look like below.
Fold it closed and draw around it onto a separate piece of card to make an extra heart shape and cut out (As shown below). Decorate all your pieces with backing paper and trim.
Take the front of your card and fold it over. I have put the point at the bottom of the heart in line with the cut out on the top of the heart as shown below.
STEP 4Add adhesive to the bottom half of the folded heart shape and attach your extra heart shape panel to this.
Decorate and job done! Don't forget to add a "stopper" to the bottom of your card to stope the heart from slipping.