Earn 3% Back at Amazon.com
Earn 2% Back at gas stations, restaurants and drugstores.
We use it exclusively for gas... It sits in the sunglass holder in each of our cars.. 2% is hard to beat without true credit card hacking. We do also use it for all our amazon purchases which is nearly 95% of stuff we buy.
They do often give you bonus rewards too.. Around this past christmas, Amazon card holders received a bonus 25% off all childrens toys, so I bought an amazon fire tablet (which was included) for 25% off.
The only other hack I can think of would be using Amazon's subscribe & save. We generally use amazon for toiletries, diapers, wipes, and some kids clothes.