I made some bad money decisions about 8 years ago and fell into some hardcore debt action, up until the last year I was still feeling aftershocks. But now I'm forever done with that bullshit, and I will never do it again. (living on credit)
Avoid credit cards and banks AS MUCH AS YOU CAN.
Even if you think it's a pain in the ass to get money orders for bills and shit, do it anyway. The less number of times YOUR money gets touched by a bank, the better off you are. Once you start keeping your expendable money in the bank, they have all kinds of dark intricate 'policies' that are designed to plink you for a few extra bucks here and there and it happenes to everyone.
As for credit cards, what kind of sucker wants to pay interest on a candybar, beer, or a bill? Spending only the money you actually have helps you learn how to adjust your lifestyle to suit different budgets, because sometimes you have to buckle down and live in buddha mode. I always feel secure because I realize I can live with a lot less when needed.
Don't even think about getting any loans.
Don't even think about getting any credit cards.
If you can live without those two things, it feels fucking awesome.