There are two approaches 1 would be to go after new cards with sign up bonus' for travel rewards. Chase UR would be a good choice if you want to earn points for free travel, if you have a business a CIP is the most lucrative sign up bonus at this time. These points can be cashed out as well.
The other option if you really aren't interested in opening different credit cards and want more to optimize your savings on gift cards and basic spend would be through a cash back card. I think one of the best options is a DiscoverIt with the first year match. Currently, DiscoverIt has 5% back at grocery stores, so 5% back right now and an additional 5% back after your first year with the card, I know many use fuelpoints to sweeten the deal and get better than 10% off from your gift card purchases at the grocery stores. Each quarter you can spend up to 1500 and earn the 5%. Then anything else you spend on the card is 1% back now and 1% back in a year. Unfortunately, this year I don't think the rest of the quarters are as lucrative as there were last year at least when it comes to gift cards, as next year is gas stations, uber and lift, followed by restaurants and lastly
amazon (no warehouse stores this year).
On the first approach you would need to spend a certain amount in a time frame, the CIP is $5,000 spend in the first 3 months for the 80,000 UR which then can be used via there portal at 1.5cpp for travel, transferred to travel partners or cashed out at 1cpp. Feel free to ask questions. No way to churn is a bad way.