I just eyeball it, snd that's prob the source of variability in flour needed to get it to cohere. I suppose I should start being more scientific, is 50/50 pretty normal?
OH! also, you need to do equal parts by weight since flour weighs way less in volume than water you will have 120+% hydration starter and it won't grow!
I feed my starter different depending on my intention.
If I'm planning on making bread with it, I will feed it 90g water and 90g flour. 100% hydration is the easiest way to calculate how much starter you want in your recipe because you can remove equal water and flour to adjust.
If I'm just feeding to sustain, I will feed 80g water and 100g flour. The lower hydration slows the feed and allows you to wait longer between feeds.
Doing the above and keeping in the fridge can allow you to literally wait weeks between feeds. If your starter separates and gets a skin it isn't dead! Just scrape all but what sticks to the bottom and feed again.