I made a card using the Avery Elle "It Bites" recently and had some left over fish stamped and coloured floating around my craft table of doom, so decided to use them to make a few quick cards.
I applied distress oxide ink to an acrylic block, spritzed with water and squashed down on a 4x4 Ivory card blank. This gave different effects depending on how much ink and water was applied and whether I overstamped in a different colour. I glued the fish on and stamped some bubbles from the set with versafine black ink and also the sentiment from Simon Says Stamp's Keep Swimming set. Simples!