I like the age-old motif of hearts and keys. It never goes out of style and always seems so genuine and proper. I also like gags involving swallowing a key like in "Arrested Development" so with these cupcakes I'm all set.
When I was a kid, the closest I ever got to decorating my own cake was a cookie and a little tube of gel icing. I had plenty of fun with just that. Imagine how awesome it would have been if we had edible paper back then? I can't say I'm not a little jealous of kids these days.
I love the motif of kind of spiky flowers like this on baked goods. It contrasts nicely with the soft roundness of the cake itself, don't you think? I don't know much about flowers but I bet you guys do; are there real life spiky flowers like that out in the wild?