Stay out of bad debt

Choose your friends wisely.
Hang out with friends who talk more about how to make money than how to spend it.

Carry cash.
If you don’t have the discipline to pay off your full credit card bills on time, take cash along with you and leave your credit card at home when you go out.

Pay in full.
If you buy something on a credit card, disregard the minimum-payment option, and pay for it in full when the bill comes.