Preventative cleaning is the most natural way to keep bronze looking good, by using a clean cotton cloth to prevent the build-up of dust and other particles. To make bronze shine, add a little bit of olive or other natural oil to the rag when wiping.
While bronze, a corrosion-resistant copper alloy, is generally long-lasting, it can deteriorate over time if it is exposed to the elements. For pieces that need a little more cleaning, a saltwater solution is ideal. A small brush helps to reach into and clean crevices. After cleaning, use a dry cloth to give the bronze a shine.