Put dry rice, white or brown, into a pot. Shake it down into a flat layer. Now lay your hand on top of it as you pour in water; the water will first fill the spaces between the rice and then rise above it. When your finger is immersed, stop. Assuming that your pot is anywhere near the right size for the amount of rice you're cooking, you now have the correct amount of water for it.

The rest of the protocol for rice is, of course, to put a lid on it, bring it to a boil on high heat, turn it to the lowest heat you can get, and not lift the lid for at least ten minutes. Under any circumstances. After that, different rices seem to require different cooking times; I buy large bags of Calrose so I can rely on the same characteristics for months at a time.