What’s mathematically the best way to buy a car?

I’ve seen plenty of posts of what NOT to do, but I haven’t seen much about what the best way to purchase a car is. From what I can tell it’s some combination of the following things: - buy a car that’s 3-5 years old with relatively low miles on it - purchase cash only if you can - use your old car for as long as possible

What else should be on there? My 2007 Camry with 190k miles on it is approaching the end of its life and I want to make sure I’m ready for when the time to purchase a new car comes around.