It seems for every person with a starter there is a different way to feed it.
I'm a once a week baker. I like to keep around 200g of Betty White (my starter's name). I just like this amount. I do a no discard method. I calculate how much starter I need for the week, then I empty all Betty into a mixing bowl. Now I add 1:1 of water and flour for what I need and usually a little bit more to compensate for any loss on the spatula and the bowl. Then I leave it in a warm spot for a few hours, however long it takes to become bubbly. At this point I make my dough. And put the leftover 200g back in a newly clean jar for next week. If it's under 200g I will give her a small snack before putting her back in the refrigerator.
Pictured is the one time I tried to feed Betty White in her jar.
I feed infrequently, maybe once every 3 weeks. Starter lives in the fridge and it gets fed when I bake.
Equal parts water and flour go in to make up for how much I used for the bake and then I let it rise to double in size. It goes back in the fridge until next time.