Best advice that my dad ever gave me was to avoid being in debt to anyone if you can avoid it. Yeah you can't avoid getting a mortgage but if you get one pay it off as quickly as you can. Yeah you can get a new car on finance but you could probably pay cash for a decent one if you saved...
I don't generally charge anything I can't pay for with cash, debit or a check. That said, I charge almost everything, even utilities so I can get the rewards points. I redeem those for statement credits to reduce the amount owed and pay off the rest every month. I could pay for it all without using a CC, but why when they're paying me to use them via points?
I bought a used vehicle earlier this year and put it on a CC that was still on a 0% interest promo. Got the rewards points, reduced the balance and paid the rest off over a few months before the promo ended.