With the internets and all this may be redundant, but it's handy to keep plain, dry, shredded coconut on hand in the pantry (not toasted, not sweetened). You just need hot water, cheesecloth, and dry shredded coconut to make great coconut milk! You can also grate up fresh coconut--the page below details the process.
Dried/dessicated coconut instructions nabbed from:
http://www.asianonlinerecipes.com/cooking_guide/coconut_milk.php They include labor-saving use of a blender (see below)!
Using desiccated coconut : Many cooks use desiccated coconut for making milk. It is much easier and quicker to prepare than grating fresh coconut, and in curries you cannot tell the difference. Put 2 cups desiccated coconut in a large bowl and pour over 2 1/2 cups hot water. Allow to cool to lukewarm, then knead firmly with the hand for a few minutes and strain through a fine strainer or a piece of muslin, squeezing out as much liquid as possible. This should produce approximately 1 1/2 cups thick coconut milk.
Repeat the process using the same coconut and 2 1/2 cups more hot water. This extract will yield approximately 2 cups of thin coconut milk.
Using a blender : With an electric blender you save time and a lot of hard work. Put 2 cups desiccated coconut and 2 1/2 cups of hot water in blender container, cover and blend for about 30 seconds. Strain through a fine sieve or piece of muslin, squeezing out all the moisture. Repeat the process using the same coconut and 2 1/2 cups more of hot water.
Sometimes a
richer milk is required. For this, hot milk replaces the water and only the first extract is used. However, a second extract will yield a flavorful and reasonably rich grade of coconut milk that can be used in soups, curries or other dishes.