Every cat lover not only wants to care for their cat, but also wants their cat to live as long as possible. If you want to spend as much time with your cat, then do your best to increase its life span.
First, start with its diet. Feed your cat a healthy and nutritious diet. By giving your cat only healthy foods, you can reduce the chance that it will get obese, which will create further health problems.
Also keep your cat mentally stimulated. This could mean games and puzzles to keep your cat active, but the goal is to keep your cat happy. Happy animals (and humans) tend to enjoy life no matter how long it may be.