A Google purchase, say a Nexus on your Amex Business Gold card will get you 2 bonus points per dollar, it's Advertising.
If you need to purchase stamps, instead of the post office use a freedom in CVS (now) for 5 bonus points, or buy in shoprite on Amex Blue 6% cash back...
The obvious one, if shopping at department stores, pick up gift cards in shoprite...
We have the maximizing on freedom thread that discusses purchasing gas gift cards for 5% all year long (and cash price).
Ink cards for gift cards in the office supply stores (5x bonus)