My first loaf, tastes delicious! Thank you for the great guidance!

Hello! Thanks so much for teaching us all last night. My starter has doubled in size and I put it into a bigger jar and will feed it again today before putting it into the fridge. I have one question: your write-up on feeding my starter has one section I’m hoping for clarification on. You indicate measuring to feed the starter which I believe is different than the rubber band method, correct? You state “you can choose a clean jar or “eyeball” it from there. That’s the part that’s throwing me off I think. 😊