To complete the card, I would stamp a single image onto co ordinating smooth card, double mount it on ivory and green (or blue for the shells) and place it in the centre of the card. Of course, that's just one option.
|SALT AND ACRYLIC WASH|
|DISTRESS INK & ACRYLIC BLOCK BACKGROUND|
|INKED CRUMPLED PAPER|
|DISTRESS INKS + CRUMPLED PAPER|