Some cats are prone to urinary tract infections, especially males and tabbies. I have a male tabby cat so I was forced to come up with a solution. My concoction I've whipped up for Owen, my cat, is outlined below.
First and most importantly, I add a product called Enzymes pH (made by All the Best Pet Care) to his food. I do this every time I feed him. If you don't live in the Seattle area you can place an order over the phone. I'm not aware of anywhere you can purchase it online. If you know of somewhere, please let me know. You can always create a quick, decent substitute by mixing cranberry extract and vitamin C (1:1 ratio). Note: I've done this before when I didn't have any Enzymes pH and it has worked, but I do not know how well it works long-term.
Next, I bought a Drinkwell Pet Fountain. This product was invented by a veterinarian. It works by continuously circulating water, which prevents your cat from drinking stale, sitting water. Mine operates in phases, however, as my cat is very picky and only seems to want to drink water from places he's not supposed to (the sink, our cups, and the dog's bowl). I get frustrated with him not drinking from it and let it empty. I may try replacing the dog's bowl with a bigger pet fountain. Anyway, this tactic has been recommended by several veterinarians as a way to encourage your cat to drink.
If you're going to do one method, buy (or create) Enzymes pH. Using that alone has been extremely effective at preventing urinary tract infections. In fact, Owen has had just one in recent memory, which was due to the stress of having a new kitten in the apartment.
Note: I plan on discussing how to cure a urinary tract infection yourself in a forthcoming post.