Cut out the card base, or use a pre-cut sized card if you have any on hand. Cut a heart on the front of your card. Score and fold. Cut the clear plastic sheet as well, smaller than the card front but bigger than the heart. Cut a second sheet of cardstock smaller than the card front to use as the backing for the clear plastic sheet.
Punch out your small heart shapes from different colored cardstock. I also punched out some hearts on glitter vinyl to add as accents.
Apply a layer of Mod Podge onto the clear plastic sheet. Start adding paper hearts, distributing them as you’d like.
Periodically check the placement of hearts to see if you have areas that you would like to fill in. Continue until the area that will be visible through the front is full.
Once you are happy with placement, add a layer of Mod Podge on top to seal the hearts and make sure they don't come off. Allow it to dry before proceeding onto the next step.
Finally, assemble the card by using tape to hold the clear plastic sheet in place, and then covering with the second piece of cardstock for a clean and finished look.