Also on these boards
Bottle Cap Coasters - not a tutorial but I like the idea. Use canning jar lids, bottle caps and resin.
Bottle Top Coasters -- looks like you can hot glue the tops together and put felt on the bottom so they don't scratch the table, or you can drill a tiny hole on opposite sides of each top and "sew" them together with wire/fishing line, then attach felt to the bottom. Very cute!