General
If you want to add comedy to a generic photo card, try using photos taken in a bubble bath. Whether it's an adult, child, pet or random household object in the bath, lots of bubbles are always a fun addition to the scene. Alternatively, let your children dress up in your clothes to create fun family photo cards that you can send to relatives and friends or keep for your own amusement.
Birthday
What can be more fun than playfully kidding someone on her birthday with a funny photo card of herself? Present the birthday girl with a card featuring one of her cutest baby photos, a photo of her on a roller coaster or one of her laughing hysterically. Alternatively, use a photo of the birthday girl's pet. Dress her cat or dog up in human clothing and shoot the ideal comic photo to put on a birthday card.
Valentine's Day
If your life partner has a great sense of humor or you want to make your secret crush laugh, a funny valentine may be just the tonic. Use a photo of yourself dressed up in a silly costume to show you don't take yourself too seriously, or take a photo of a heart-shaped cushion in the funniest, most random place possible. The sight of such a cushion sitting in its own seat on a train or at the theater is likely to make anyone laugh.
Halloween
If you want a photo card that makes October 31 more funny than scary, use a photo of yourself or the card's recipient in a funny Halloween costume. Comic costumes could include your favorite cartoon character, an iconic comedian such as Charlie Chaplin, a giant rodent, your own pet or something that requires cross-dressing. If you don't want to go for a full costume, stick white, rectangular mints in your mouth as fake fangs and take a photo of yourself baring your "vampire teeth."
Thanksgiving
Give Thanksgiving celebrations a lighthearted feel by reminding everyone of hilarious incidents from previous Novembers. Find those photos of a freshly-roasted turkey that was dropped on the floor, someone sleeping in front of the television during the football game, or a child with dessert smeared all over his face, and incorporate them into your photo cards. You could also try using a photo of a toy or plastic turkey wearing sunglasses or a hat.
Christmas
If you like both tradition and humor at Christmas, take some hilarious historical photos to put on your cards. Dress the whole family up in vintage clothes or as historical figures and take a photo using the sepia filter on your camera. Alternatively, put a Santa hat or fake reindeer antlers on a child, pet or inanimate object, shoot a photo and put it on a card to get the recipient into the Christmas spirit.