You can get the most from your cash back credit cards by using them for all expenses that can be put on a credit card without incurring extra fees that would eliminate any benefit. You can also pair a flat-rate card with a tiered or rotating cash back card to take advantage of the best of each card. For example, when there’s a quarter where you get higher rewards at warehouse clubs like Costco, try to plan your purchases to fall at the beginning and end of the quarter if your budget allows.