One popular strategy is known as credit card churning — opening and closing cards to earn sign-up bonuses and rewards.

It earns eye-popping rates at some of the biggest brands in America, including Amazon, Target and Walmart, plus 3% back in other popular categories. But there's a rewards cap and an annual fee ...

If you're on a Galaxy Fold, consider unfolding your phone or viewing it in full screen to best optimize your experience.

You get bonus points for spending on travel, dining and some everyday purchases. Points are worth more when used to book through Chase.