Here are some tips for you.
1) Get yourself a reward credit card. People usually prefer cash back rewards, but other types of rewards can also be valuable - airline miles or flexible points that you can exchange for cash or for frequent miles.
You can get a card that offers 5-6% of maximum cash back on certain categories, but it is more beneficial to have a flat rate card - with 1.5-3% rewards on every purchase.
Best flat rate 2% rewards cards today are Citi Double Cash and Fidelity AmEx, both have no annual fee.
More on cashback cards here
2) It is not easy to calculate if the card rewards rate will worth paying the annual fee, so the easy rule is to focus only on no annual fee cards - there is a plenty of them today for any taste
Some of the best no annual fee cards here
3) If you carry a balance on your credit card, you should focus not on the rewards but on low APR on your card.
With 0% introductory APR for 12-18 months, you can have a good interest break, but it is generally better to have a low regular APR card (8-10% ongoing APR), like Simmons bank card or Barclaycard Ring.
Excellent Credit Required - Applicants that do not have excellent credit will not be approved
Low 8% variable standard purchase APR and platinum benefits
No balance transfer fee for balances transferred in response to this online offer
No Annual Fee
More on low APR credit cards here