Stained glass objects will last generations, but there are a few things to know that will help them look better for longer. 

Over time the metals will naturally oxidize, remove any discoloration with a wet q-tip or soft cloth. Never scrub with an abrasive material, this can remove the patina and scratch the solder. Car wax (carnuba) can be applied and buffed to bring shine back to dulling patina, as well as remove oxidation. If after a year or so you feel it needs a pick-me-up, I have a kit that contains patina touch-up and a small chunk of wax that will bring it back to former glory. If you're not up for it, you can contact me for a good deep clean and polish. If anything breaks, contact with a description of the problem and we can talk about options.