I do this one of two ways. I either freeze two cups of cooked rice in a plastic freezer bag for a complete meal like a stir fry or I shape the rice into balls. Each ball is a single serving. Be sure to densely pack the rice ball, so as little air as possible gets in there. I wrap the balls in plastic wrap and then freeze on a cookie sheet. Once completely frozen, I place the balls in a plastic freezer baggie.
Make sure as much air as possible is out of the bags. To reheat a bag of rice, simply open the top of the bag, add a teeny bit of water, and microwave for a minute or two. To reheat a rice ball, unwrap the ball, place on a plate, sprinkle with water, and microwave for a minute. If you are using the rice in a recipe, you can just throw it in the pan with whatever else you're cooking. You can do the same thing with the slow cooker. It doesn't take very long to thaw.
And now you know.
I said rice and balls. Oh, yes, I did.