To make seashell wine charms, simply glue the suction cup (non-suction side) to the back of a shell.
For best results, place the suction cup on your protected work surface, suction cup down. I find freezer paper works well here to cover your work surface. Add glue to the top of the suction cup and rest the shell on top, holding the shell lightly until the glue sets.
Let the glue dry completely before using your wine charms.