There are a lot of new products plus your needs and resources change over time. Your mortgage payment is probably your single biggest payment and if you haven't yet, now is the time to refinance with rates at all-time lows. I agree with Tarnow's rule of thumb. If you can keep your payments down, it might also be a good idea to roll in some other debts too. And if possible, shorten the term of your mortgage.
Credit cards are a necessary evil.
Just try renting a car without one. So shop and compare terms. If you pay off the balance each month, shop for the lowest annual fee. If you carry a balance from month to month, the interest rate is most important. Put your investments and accounts in one place.