Most pieces need less cleaning than expected. Begin with a dry microfiber cloth. If the product notes permit moisture, use a barely damp cloth and dry the surface immediately; avoid soaking, ultrasonic equipment and household chemicals.
Store jewelry separately so harder surfaces and metal fittings do not scratch neighboring pieces. Lift home objects with two hands, keep felt contact points clean and avoid unstable shelves.
Sun and heat can change some materials or adhesives over time. A display position away from strong sustained sunlight, radiators and wet areas is the cautious default. Follow the care instructions supplied with the specific product when they differ.