Good question @Dave Daniel
First thing is you need to love your car to no ends, in case of Gaurav it is literally as any signs of hate and his Pajero would not start up. As per the old books what I learned from my dad, may God Almighty rest his soul in peace, every morning check all the oils and fluids to check if the level is A OK. A visual inspection while the bonnet is open will reveal any discrepancies, get them checked in time and repair small before it effects any other parts. Change the oils, plugs, filters, timing belts, etc on time and avoid any big expenses. If there is any discomfort while driving, any noises from the car, any vibrations, anything that you feel is not right, get it checked immediately, sometimes a small problem solved can save you from bugger expenses. Use methods like fuel injector cleaner and other such products at least once a year just to be sure that all is well on the inside.
He used to say that the general maintenance of a car does not make your car run smoother, it just makes sure that over time your car keeps running as smoothly as when you first got it.