Cat owners whose cats are 15 years old and up. What’s the secret to feline longevity?

I want to hear all your tips on what your feeding your cat, play times, care techniques to extending your cats age. Obviously if your cat is 15 years old and more you know what you’re doing.

Edit: Hey Guys, thank you so much for the posts. I feel better equipped to help my 2 Meow factories live a better and more enriched life!