I use:
Amazon card for Amazon purchases. 5% back on all purchases—can be cash or used again on Amazon.
Costco is 2% at Costco, 3% on restaurants and travel, and 4% back on gas. Also matches another 2% in Costco purchases as a gift card.
Both above do 1% on everything else.
Apple Card with Apple Pay does 2% on any Apple Pay purchase, which beats the 1%. I think it’s 3% back on Apple purchases, which aren’t frequent but pretty good for when you pay App Store fees and get the odd new computer or phone.
This all adds up for us (family of 4) to over $1k each year easy, probably closer to 1.5k. Ramsey would have you forgo this money to bolster his ideology and because he doesn’t trust his listeners to be responsible. In 20 years with a credit card I think I’ve paid $5 in interest, because of one purchase I needed in grad school that I needed one extra month to pay off. Otherwise we pay it off each month in full.
The best is getting the rewards on reimbursable items. Flights get 3%. One time we had pharmacy fills that we paid about $8k/mo on a credit card for 5 months, reimbursed within two weeks before bill was even due. An easy $400.
Use the tools well.