The most effective way to prevent sterling silver jewelry from tarnishing is to store it in a clean, dry airtight container such as a Ziploc bag or Tupperware.
You may want to use an anti-tarnish strip with the jewelry in the container, which will help to absorb tarnish-causing elements.
Do not wear sterling silver jewelry in the shower, hot tub, or swimming pool.
Do not leave sterling silver jewelry in the bathroom where it can be exposed to high humidity and moisture.
Minimize the contact to hairspray, perfume, and lotion by using these products sparingly and prior to wearing your jewelry.
After removing your sterling silver jewelry, clean with a soft dry cloth prior to storing it.