Water-to-coffee Ratio
Grab a scale and start with a 1:17 ratio. (You can always adjust if you want the flavor to be stronger after the first cup.)
For example...
Suppose you have 35 grams of ground coffee. To brew at a 1:17 ratio, you would need 17x that weight of water. 595 grams, or about 3-4 cups of coffee.
WATER TEMP
Brew your filtered water to 205 F. You can use an electric kettle, or a stovetop kettle with built-in thermometer.
Grind size
A medium-coarse grind is a sold choice for pour overs. The grounds will feel like rough sand.
Good to know...
If the grind is too coarse, you'll get under-extracted coffee with a salty or medicinal flavor.