1. Don't carry a large balance so you won't have to pay high interest charges.
It may not be easy, but it is simple: "pay yourself first." Save a certain amount for
life's necessities and for your future, and do not put spending on a card unless you have enough money left to pay the card bill on time.
2. Avoiding late fees is fairly easy. If you forget to pay bills promptly, you can pay online on the due date for free (or even set up an automatic monthly payment.) Or you can do a "check by phone" for about $10. If you keep up a good payment record, you can ask them to waive a late fee at least once.
When we're responsible about bill-paying and spending, other credit "traps" can't ensnare us.