Please protect your jewellery from substances that may cause damage - for instance, foods containing acids, your perfume, hair or body spray, and even woollen clothing. Try to remove all jewellery before showering, domestic work or swimming, as water contains chlorine, which is a big accelerator of tarnishing.
Stretch bracelets will keep their shape for longer if they are not overstretched when putting on and taking off - just gently roll them on and off. The beads are made from natural stones, which may chip if they fall onto hard surfaces or are struck with heavy objects.
Although there is no way to protect your silver jewellery from turning black, as silver reacts with so many materials found in everyday life (including your skin!), your jewellery will always benefit from a regular, gentle polish with a silver polishing cloth or paste. It is also good to keep the silver pieces in a linen bag with silica gel pouch (which absorbs humidity) and ideally in a sealed box.