Polishing silver at home without wearing it away

Sterling silver darkens because the copper in it reacts with the air (sample note). It is not damage, and it comes off.
Use a silver polishing cloth and rub along the piece, not in circles. Skip toothpaste and baking soda: both are abrasive and take a little silver with them every time.
Store silver in a closed bag with an anti-tarnish strip, and wear it often: skin and clothes polish it gently. Bring it to the counter once a year and we polish it on the wheel for free.