Avoid "Wipe & Rinse" Silver Cleaner
You've probably heard people recommend the wipe and rinse silver cleaners (tarnish removers) for your silver jewelry. Don't do it! Using silver cleaners & tarnish removers from the grocery store will very often pit your silver making it dull.
There are 2 options I recommend for cleaning the tarnish from your silver jewelry. One is taking it to a reputable jewelry store. Most of them will clean a piece or two free of charge. The other method is using the Sunshine® polishing cloth I provide in orders containing silver and copper items or chains. These cloths are pre-treated with a high-quality, micro-abrasive polishing compound that is safe for polishing silver, gold, copper and other metals. Never wash your polishing cloth.
One thing to keep in mind...if you have jewelry that's oxidized, the cloth will remove the oxidation. On my textured pieces, I recommend you rub the cloth only over the raised design to keep the deeper recesses oxidized.
For the enamel jewelry, all you need is a damp cloth. Vitreous enamel is actually glass powder that is fused to the copper or silver using very high heat, between 1450° and 1500°. You can use a mild soap if you like, make sure you rinse well and dry with a cloth or paper towel. The same is true of Niobium ear wires.