An occasional rub with a silver cloth should keep these earring lovely and shiny.
When not being worn, keep in the acid-free tissue paper and avoid perfumes and deodorants as these tarnish silver quickly.
If really dirty, use either foaming silver polish with the sponge that is provided (or an old toothbrush) or silver dip. (Goddard’s make both, which is widely available.)
Then wash in soapy water to remove the polish, rinse thoroughly in clean water, dry with kitchen towel to avoid watermarks and leave to dry out completely somewhere warm.
hide cleaning instructions.