Pewter & Tin
Cleaning is best done by washing in warm soapy water, followed by thorough drying. A silver polishing cloth is all that is needed to maintain a high polish. For more serious tarnishing after long periods you can revive the pewter by rubbing with a very fine abrasive paste such as Autosol.
Pewter and tin are relatively soft metals and do not like being twisted and bent repetitively. Weak spots can develop leading to metal fatigue.
Never place pewterware in a dishwasher, as the high temperature and chemicals will react adversely with the metal.
Silver tarnishes quite quickly when left in a humid atmosphere for any length of time and not worn. The proprietary Silver Dip is very good at removing this oxidation. Just follow the instructions on the jar.
A silver polishing cloth will also bring back the high shine. Please be aware that strong chemicals such as bleach can cause silver to tarnish and sometimes turn black especially if sulphur is present.
Silver is not a particularly hard metal and if you intend to do manual labour where rings could be in contact with stone or bricks it is best to take them off first.
Being such a strong alloy has many attributes, however, oxidation (tarnishing) can still occur. Don’t use Silver Dip on bronze. Rubbing with a silver polishing cloth should suffice but more serious oxidation can be removed with a fine abrasive paste such as Autosol. With constant wear tarnishing is less of an issue as the regular rubbing against items of clothing tends to keep it clean.