If you have a habit of wearing your costume jewelry to the beach, yet want to prevent this same jewelry from tarnishing, you should rethink that practice. The sand and salt water are not good for such jewelry, therefore brass, copper, gold plated, and silver plated pieces should be treated with extreme care; especially if those are favorites.
Do not spray cologne, perfume, and / or lotion onto your costume jewelry when worn, as that can result in tarnishing. A helpful suggestion would be to put your cologne, perfume, or lotion on areas which will not be in direct contact with your jewelry.
Do not wear your jewelry when you plan to clean your house with harsh chemicals.
Whenever your brass or gold plate jewelry tarnishes, you could clean it with lemon juice mixed with a little cool water in a small bowl or container for a few minutes. Once your jewelry is cleaned, you should rinse it out in cool water, then dry it with a paper towel or cotton cloth.
You could clean your copper with ketchup; just use a cotton cloth, old T-shirt, or paper towel. Rinse in cool water, then dry with paper towel or cotton cloth.
Use toothpaste to clean your silver plated jewelry. It is also a great idea to clean your sterling silver or gold. Rinse in cool water and dry with cotton cloth. You will get a beautiful shine on your jewelry.
Whenever I run out of jewelry cleaner, I sometimes use this procedure which works well for me.
Do not use this technique with jewelry containing semi precious stones such as turquoise, pearls, coral, fluorite, moonstone, malachite, obsidian, blue lace agate, moss agate, hematite, pyrite, abalone, and amber because the hardness on these stones is below seven. Most gem stones have a hardness which identifies the strength of the gems.
I like to experiment with different ways on how to clean jewelry and share it with jewelry designers and customers.