I have seen similiar earings here before, but here's my version.
sorry the pics aren't great, but I think you can get the gist of them.They are made with flattened Bacardi Breezer bottle caps.
Here the basic instructions:
1. Wash and dry bottle caps.
2. Use pliers to gently pull out the 'fluted' edge of the bottle cap.
3. The bottle caps I used had a waxy/rubbery substance in the bottom, you need to remove it to make the bottle caps flat. Run a craft knife or blade around the edge of it, then slice through the thick rim of the substance. You should now be able to pull the substance off the cap.
4. Place the bottle caps face down on a hard surface, you may need to place a piece of thick fabric (I used old jeans) between the caps and the surface to protect them.
5. Use a hammer to flatten the bottle caps.
6. Make holes in the bottle caps to attatch earing findings etc. If you plan on using jump rings keep this in mind when macking the holes to ensure they fit. I used a nail and hammer to make my holes, but I'm sure there is a better way.
7. Attatch earing findings, beads etc to make beautiful earings.
Those intructions might seem a bit odd, I'm not very good at explaining things, if you have any questions, just ask.