My mother and my father both have very particular ways in which they make fluffy rice. The results, while both fluffy, are quite different from one another. My mother says that her method is Persian in origin, and my father says that his is Vietnamese. I will have to take their word for it...they, not I, lived in those places. My mother's method yields soft, separated grains, the kind of rice you find in India and (not surprisingly) goes extremely well with Indian food. My father's method yields grains that aren't exactly separated, but aren't sticky or heavy either. His rice is very dry and light--you've probably never had rice with this texture. (I haven't aside from his.) Both of these recipes work best with long grain white rice. If you have a different sort of rice, I would suggest my mother's method, although the result won't be the same.
I've written detailed instructions here, but once you get the hang of it both recipes are quick and easy--you can make them in about 30 minutes, while you cook whatever it is you're going to have with the rice. Basically, they involve boiling, draining and steaming.
My mother's rice
Heat plenty of water in a pot. Make sure you have enough water to let the rice swim freely around. While it is heating, rinse the rice: in a bowl, add cold water, let sit, stir, drain, and repeat. When the water is boiling, add the rice, bring back to a boil, and then turn the heat down so that the rice is just simmering. Let it simmer, stirring occasionally, until the grains are *almost* done (they should have just a little bite left to them). Turn off the heat and drain the rice in a colander. Add a little butter to the bottom of the pot, put the rice back in the pot, mix in a little bit of salt (and a pinch of saffron, if you want), cover the pot completely with a clean kitchen cloth, and return it to the stove. Turn the heat on very, very, very low and let it steam for about five minutes without lifting the cloth. At that point, fluff it with a fork and see what it's like. If it's not quite dry enough, steam it for a few more minutes. If you want a golden crust on the bottom—a Persian, not an Indian feature—heat it on medium-low heat for a few minutes more, and make sure you have put a nice little bit of butter in the bottom.
My father's rice
This requires precision, just like baking: the directions are not hard, but they must be followed exactly. Heat plenty of water and rinse the rice, as before. Make sure you rinse the rice very thoroughly (maybe 3 or 4 times). Add the rice to the boiling water and boil for exactly 2 minutes. Drain and return the rice to the pot. Add new cold water until the grains of rice form "islands": some grains of rice should stick out above the surface of the water, forming little islands, but no grains should be fully out of the water. Imagine arctic waters with lots of little chunks of ice floating on it, and you'll get the picture. (Whew, now you're done with the crucial step!) Turn the heat up until the rice comes to a boil again, about 1-2 minutes. Then turn the heat down to very low, cover the pot with a tight-fitting lid (you don't want any air escaping), and leave it alone for about twenty to thirty minutes. It's done when the rice is dry, soft and fluffy.