Gather some fun paper (it will be your border), plain paper, scissors, double sided tape (I use scrap book sticky tabs for photos), pens/markers, and of course dice. You can use a single die, or find a way to incorporate a full set.
Write your little notes/messages on plain white paper (make sure to leave enough space for your dice wherever you intend to place them) and cut them out.
Put the sticky tabs/tape on the back of your message.
Stick it to the scrapbook paper, and cut around it, leaving a border.
Put sticky tabs on the bottom of the dice (these stick very well, yet also easy to remove them so they can be used).
Stick the dice to your cards. You can write sweet messages, make a game out of it, or have them roll for a prize. I personally chose to make 2 sweet cards and one that was a bit naughty, but you can always have them roll for dinner, a massage, etc.
Feel free to add stickers and such to decorate it/give it more of a finished look.