I'm submitting this card to two challenges, Simon Say Stamp & Show's Water challenge and A Blog Named Hero's Freestyle challenge.
I started the card by making the water background. I used a mixture of metallic gelatos, distress reinkers and water. The original mix was too uniform (I just blended all the above together into a mass), so I added some more drops of ink and rubbed them in as smears. I was smart enough to use watercolour paper, so the amount of liquid I added didn't warp the page. I wanted a bit more dimension and so added white streaks to indicate waves. My white gel pen didn't work on the gelato, so I used a white paint marker I got. I don't normally use it as the colour tends to get washed out with whatever clear medium they use for the marker, but the watercolour paper accepted the extra liquid, and I was able to get enough white out to create the effect I wanted.
The shells were also stamped on watercolour paper using Hero Arts stamps. I originally tried stamping them in gold gelato, but the image wasn't dark enough, so I stamped it with black stazon, then inked over top in gold. I also rubbed some more gold on the paper, so it wouldn't have a white background. Interestingly, the stamped gold didn't blend, so I've still got a nice gold outline along the black. I used two small foam pads and a bit of glue to attach the larger shell, then used one foam pad and glue for the smaller shell. This gives them more dimension (as one shell is on the other) without popping the card up too high.
For the bottom, I cut a piece of yellow holographic paper. I tape runnered it to the water page, then decided it needed something more, to show the water getting onto the sand. So I ran a bead of blue glitter glue along the shoreline, and spread it over the sand.
The card is quite shimmery, as even the water and shells (thanks to the metallic gelatos) have a glimmer to them.