I've used Gorgeous Grunge and Sassy Salutations here for my card but Tracie whom the idea came from has used Perpetual Birthday calendar and You Little Furball as well for her card.
I'm not sure if you can tell, but I've cut the 6 from the wall and I have the card base behind showing through rather than having the positive from the die cut stuck on.
On the inside I simply stamped "have a great day" using Endless Birthday Wishes.
Here is another version I made of the same card - this time I used Blackberry Bliss as my main colour and I teamed it with the dog from Hey Girl instead of the number.
Cardstock: Old Olive, Whisper White
Stamps: Gorgeous Grunge, Sassy Salutations
Ink: Old Olive, Lost Lagoon, Crumb Cake
Other: Brick Wall Embossing folder, Little Numbers dies,