This card's fancy factor far outweighs it's difficulty factor.
I started with an off-white card base, and I stamped "Celebrate" from CTMH's "Card Chatter-Birthday" stamp set. Then I affixed the ribbon and bow. Then I punched out 18 hearts the same size in papers that kind of coordinated, but definitely didn't all match. Eight of the papers should be punched twice so you have eight pairs of hearts from the same papers.
Then glue down two of the hearts under the ribbon on the left and eight of the hearts in a strip down the right side. Then fold the matching eight hearts in half and glue on top of their matches. It's important to only glue this second set of hearts down the middle on the fold. Once the glue is dry, make sure the top hearts fold up. To make it look like the hearts were sewn on, I drew a black dashed line down the center of the strip of hearts. Here's a close-up:
That's it. No sew, now cs, no measuring, no fancy cutting!