I don't have a credit card. I only have a prepaid mastercard, which allows you to buy stuff online IF you already have the money on it. I keep a tight rein on my spending, and only put money on it when there's something important that I need to buy. If there's no money on the card, I can't spend it. And when I put money on the card, there's a 3-5 day delay from the time I take the money from my checking account until it gets to the prepaid mastercard, so impulse spending is impossible until the money actually gets there. I also try to put only $100 at a time on the card.
I did a bankruptcy and have had 2 cars repossessed. I don't want those things to happen again.
And I'm on a pretty restricted budget now that I'm on disability.