I recommend that any jewellery should not be worn at night when sleeping, not got wet e.g. not to be worn whilst swimming, showering or exercising and isn't cleaned with any chemicals.
For sterling silver jewellery, I recommend that the jewellery is contained in an airtight container, such as a resealable plastic bag when not in use. If the sterling silver does tarnish, a silver polish cloth can remove the tarnish and restore the shine.
If giving as a gift, please keep the jewellery item inside the plastic resealable bag it arrives in until you are ready to gift the item. The gift box isn't airtight and therefore keeping it in the plastic bag will keep the sterling silver from tarnishing.
For stainless steel jewellery, I recommend that the jewellery is stored separately from other items when not in use. Whilst stainless steel is durable it can scratch. If the stainless steel needs cleaning, then a damp cloth with gentle wiping should normally suffice. If not, dip the cloth in some water with some gentle dishwashing soap before gently wiping. Always wipe in the direction of any polish lines and make sure to remove any soap residue and dry the item thoroughly.