Using this cross pendant necklace is easy - just put it on around your neck and you're good to go. When it comes to choosing the size, make sure to check the size chart because different suppliers may have different measurements. If it's an Asian - sized item, opt for a larger size. As for maintenance, you can clean it gently with a soft cloth to keep it shiny. Avoid exposing it to harsh chemicals or rough surfaces to prevent scratches. Keep it in a jewelry box when not in use to protect it from dust and damage.