Method

1. Saffron should always be bought whole, not ground. Not only does it dry out when it is ground (just like any other spice) and lose valuable flavour and aroma but who's to say it's real? Having said that, the best way to get all the flavour out of saffron is to grind it and make an infusion out of it.
2. Therefore, please follow this saffron method to get the most out of it: In the morning of the day of making the rice, wash it GENTLY (it's easily damaged) and soak it in heavily salted water for the entire day until evening.
3.  Note: after soaking, it's even more fragile.
4. Take a good pinch of Saffron. Smell it, it should be earthy and sweet. Grind it in a mortar and pestle, and add some boiling or nearly-boiling water...about 2 tbsp. Let it steep in the water for about 30 minutes or more.
5.  Put a wide based pan on the heat and add some butter or oil. Put the thoroughly-drained basmati rice into the oil and give it a good but gentle stir to ensure the oil coats the grains. Add some salt to taste (+/- 1 level teaspoon) and stir again.
6. Turn heat down to about the lowest it will go. Add 4 1/4 cups of boiling water to the rice (hiss! sizzle!), stir once to make sure all the rice is spread out and in the water but not too much stirring.
7. Cover tightly, keep on the lowest heat for 30 minutes. After 30 minutes, the water should be completely absorbed and the rice fluffy and white. If not, turn heat up very slightly and leave until it is done.
8. At this stage, pour the Saffron infusion into 3 points in the rice and replace the lid. No stirring. Leave for 10 minutes.
9. When you're ready to serve, fork through the rice gently to separate it, and you'll see you have 2 colours of rice: pinky red and white. This is the intention =) you could add a little knob of butter on top of the steaming rice, but I find it rich enough like it is.
10. Tilda is the most aromatic of all the Basmati rices I've tried, and is consistently perfect. It's genuinely fed by the melting snows of the Himalayas, although you'll find lots of other "Basmati" rice that is grown elsewhere and has none of the glory. It's in an unmissable blue package. If you can't find good Saffron and it doesn't have much flavour or aroma, then you may as well buy Turmeric (recently discovered by the west as having properties against certain cancers, but used in ayurvedic medicine in India for thousands of years before the west got wise!). Just add 3/4 teaspoon at the stage where you add salt to the rice in the pot.