"4. carry insurance"

Insurance is good but keep the deductible as high as you can. The difference between a no-deductible policy and one with a high deductible is huge. Often enough of a difference to cover the higher deductible in a years worth of payments. Keep the amount of the deductible in an interest bearing account so your still covered.

Once you have the deductible covered further savings can be applied to further raise the deductible.

Beware of taking on debt through loans that require backing by insurance. Taking out a loan for a new car often requires an expensive and wasteful comprehensive insurance policy to protect the value of the loan. This can greatly increase the actual cost of a new car.

Used cars that are a few years old are often much better bargains. The lower price may allow you to pay cash and even if they are financed the required insurance can be much less costly. A double benefit.