Re-design idea:

Don't throw away any holiday, birthday, congratulations, etc. greeting cards. Instead of buying new ones you can just rip off side someone else wrote on, and turn the card into a  post card/one piece card. This will save you money, you'll be able to keep the important message someone sent you (if you choose).  Also, it will cut the space you're using to store the card in half, because half the card will be gone!