I wanted to create a series of greeting cards you've never seen before, so I made a line of under-the-sea-themed breakup cards.
After landing on the idea, I sketched out 3 different ideas.
I created the outside (left) and inside (right) of the cards.
I created a card mockup.
And placed the illustrator files on the mockup. I gave the illustrator file an almost fully transparent look so you could really see what the card would look like.
I also created a keyline document to show where the crop marks, foil, and any other important information would be.