The goal when polishing is to remove the tarnish from your silver pieces, so that they can again have that beautiful almost rosy lustrous glow clean silver has. Tarnish is a naturally occurring chemical reaction on all types of silver, where the silver on the surface has a chemical reaction turning it from the pure element silver, into silver sulfide, the black stuff which gets all over your good serving pieces that you’ve not used for a while.

Here are few tips to polish silverware. Take note that these techniques also work great for tarnishes silver jewellery as well.

• Toothpaste – This is the best for small jobs. Dab some white toothpaste onto your finger and rub into tarnish. Rinse afterwards with warm water.
• Lemon Juice – Rub silverware with paste of lemon juice and salt. Rinse with warm water and wipe dry with clean cloth.
• Ketchup – Place silver items in bowel of ketchup for 5-10 minutes. Rinse with warm water afterwards and pat dry.
• Cream or Tartar and Milk – Place silver items in bowel containing 1 cup whole milk and 3 tsps cream of tartar. Soak overnight, rinse with cold water, and wipe clean with dry cloth.
• Baking Soda – Cover silverware generously with baking soda and let sit for 30 minutes. Wipe clean and polish by wiping down silverware with damp cloth and rinsing with hot water.

The Baking Soda/Aluminium Foil/Salt/Boiling Water/White Vinegar method

• Line a pot with aluminium foil, shiny side up. Place silverware inside.
• Add enough water to cover silverware, and add 1 cup baking soda and 1 tsp salt. Very carefully add 1 cup white vinegar.
• Bring water to a boil for 3 minutes. Take out the silver items once the water cools down.
• Plunge silverware in warm soapy water and clean with clean cloth. Wipe dry with a seperate dry and clean cloth.

Reference : https://img.wonderhowto.com/img/35/67/63510688441776/0/6-easy-diy-ways-clean-polish-tarnished-silverware-jewelry.w1456.jpg