Soak rice in 2 cups (amount as original recipe is written // adjust if altering batch size) very hot (not boiling water) for 2 hours. The rice should be soft but still very raw - you should be able to snap a piece in half with your fingernail without much effort. Drain and add to a high-speed blender.
Add water, salt, and any additional add-ins (optional). Top with lid and cover with a towel to ensure it doesn't splash. Blend for about 1 minute until the date specks are very small and the mixture seems well combined. It doesn't have to be 100% pulverized.
Scoop out a small sample with a spoon to test sweetness. If it's not sweet enough, add more dates.
Pour the mixture over a large mixing bowl or pitcher covered with a thin towel or clean T-shirt. In my experience, it benefits from a double strain through a very fine towel. A nut milk bag lets too much residue through.
*You can use brown rice, but I prefer the taste of white rice milk. *Nutritional information is a rough estimate calculated with no additional add-ins and the leftover rice pulp nutrition subtracted from the total.