Well, I was going to do the photo filled heart idea. And I think I may at some time. But it just didn't work with this layout obviously. However I used the same idea in cutting out different squares/rectangles of patterned paper to fill in the heart shape. (This was a super fast technique b/c I didn't measure my paper scraps or cut with a trimmer... I just randomly cut squares and rectangles placing them in the heart as I went.) I also let my heart wander off the edges of my paper like the heart on the box. Finally, to make the heart shape more dominant among the mish mash paper scraps inside, I did some simple handstitching around it.
So, the moral of the story... be on the lookout for inspiration everywhere. Scrapbooking magazines are an obvious starting point, but don't overlook non scrapping mag ads, tv commercials, website design, product packaging, etsy, stationary/cards, etc. And if you're really organized you could create a little scrappy notebook to store all these great bits of inspiration. :)
(On this layout I used bits of the main kit, Summer Camp as well as bits from Footpath and Adirondack. And they are still available... so grab them quickly if you can! The Real Estate punch is also in the shop!)