Google for bicycle gear ratio calculators. Look at the ratios, speed at cadence and other stuff. They'll help you see where you might get some benefits. But know what your own current bike does for you and what gears you normally use on it to climb or cruise. Then you can makes some assumptions about what changing things up might do for you.
I go to this site quite often,
https://www.bikecalc.com/gear_ratios but it shows you gears that you don't have when it calculates. I've used a lot of others too, but keep coming back to this one.
You want your 1 tooth splits to be in the gears you use the most. For the extreme low range that is for those hills you seldom encounter, you can do with many more teeth between cogs.