I had some coral reef background paper that I scanned and reduced in size. I then printed on to acetate and threw some clear detail embossing powder and a bit of holographic over it as soon as it came out of the printer, which gave a sprinkled effect. I ran the acetate through my xyron with the embossed side down, so that the surface of the ATCs are smooth. The acetates were then stuck on to a light greeny blue card, and the other bits and pieces added:
In the end, I enjoyed doing this. ATCs are a good way of trying out different things (not so much wasted if things go wrong - and they did at first - I tried embossing with other powder but it wasn't effective).
The word on HS:MS:HS today is shimmer: 'To shine with a soft glistening light. Find a 'shimmer' in your space today', so I think my ATC photos qualify that that too.