Old bottle caps, even better if they've got cute patterns on the backs...
Glue and hammer, superglue might work better, but I never have any
Flatten them as much as pos, a flat surface is good for this...
Nice and flat
Or, cut some nice looking paper/card into circles,
Glue inside the cap...
And stick that in
Hammer a nail through the cap to make a little hole...
Little more difficult if you haven't flattered them!
Earring things and some wire
They make really nice birthday/christmas presents :)
- Bottle caps
- Earring wire thingys
- Wire and/or thread