Start from your spending
List your three largest categories. For most households they are groceries, dining and gas or travel.
Pick the card that pays most in your largest category, then check whether a second card covers the next one.
Finish with a flat-rate card for everything else.
Diminishing returns
The first category card often adds hundreds of dollars a year. The fifth card often adds very little.
Every extra card is another due date, another annual fee review, and another set of rules to remember.
A card you forget to use earns nothing.
Credit score effects
Each application causes a hard inquiry, which lowers your score slightly for a period.
More available credit can lower your utilization ratio, which can help your score.
Closing old cards shortens your average account age. Keep a no-fee card open if you can.
