If you live in Japan (or, well, Asia), you have a rice cooker. If you don't own one, get thee to a store and buy one. But, if you want something non-tech and have access to lots of firewood, there's a work around.
Last week, I went way into the mountains with some friends and made lunch. This is how we cooked rice: putting water and washed rice in this tin and then leaving it over an open flame.
Honestly, I'd never cooked rice this way, and I thought it was pretty darn neato.
How did it taste? Pretty good. I didn't do a taste comparison with the same rice cooked in a rice cooker, but it worked out really well. The best rustic cooked rice I've ever had in Japan was cooked in hollowed out bamboo shoots. Now that was good eating.