Drain rice but do not rinse. Put rice in blender with 4 cups filtered water, and if desired, 1 tsp honey and 1/4-1/2 tsp pure vanilla essense. Blend until smooth.
Set a large strainer over a clean bowl, and line with cheesecloth or an old, clean tea towel, folded in half. Pour blender contents into cloth, leave to drip for a while, then gather up sides carefully and squeeze through liquid. Discard rice solids.
Pour rice milk into a bottle, cap, and refrigerate. Shake before using.
Cooked rice method
Put 1 cup cooked rice (again, any kind) in blender with 4 cups filtered water and optional flavourings as above. Blend until smooth. It is not essential to strain this type, as the result will be much less gritty and much smoother, but I do so anyway - straining through cheesecloth as above. However, take care when squeezing it, as the fine solids will squeeze right through the cloth.
Bottle and refrigerate. Shake before using.