I wanted to something like this when I saw a similar project in my friend's bathroom that her boys had made. I also thought it was the perfect way to display the shells we collect at the beach. Then, I found this step-by-step explanation, so when we headed to the Beach last weekend, we took along all the supplies and brought home these finished projects.
As always, I'm happy to admit my mistakes so you can learn from them. Next time I would not add the grassy stuff that I added. I'd stick to shells, rocks and feathers. I now have algae growing around the grassy stuff which, of course, is kind of gross!