No one piece of potentially preventive advice will do for all stone formers, especially where diet is concerned. You'll need the advice of a physician knowledgeable about the different kinds of stones. Drink plenty of fluids. This has always been the mainstay of stone prevention, and can cut your risk of recurrence by up to half, even if you do nothing else. Go easy on alcoholic and caffeinated beverages, which tend to dehydrate.
Sufficient fluid keeps the urine diluted and decreases the risk of stone formation.
You may have to measure your urine output until you can gauge how much fluid you need . Some find it's beneficial to eat less animal protein, though this is controversial. You need not become a vegan. Your doctor may advise you to avoid foods high in oxalates, including tea, rhubarb, beets, and spinach. Stone formers were once told to avoid calcium, but newer research suggests that getting the recommended amounts of calcium may actually help prevent stones in some people.