I always thought making your own nut milk was a long process needing lots of special equipment, but I was happy to find out, when I actually looked up how to do it, how easy it is! And the only equipment you need is a blender / smoothie maker and a nut milk bag - if you have a blender in the higher price ranges, the process will probably be a bit quicker, but you don't need anything expensive.
I used 2 coconuts to make close to 1 litre of milk. I use mature coconuts because I haven't ever seen green ones around here, but it doesn't matter, mature coconuts are perfect.
First pour the water out of the coconuts, you don't want to waste that because it's nutritious. You're anyway going to use this water when making the milk, but if there's no water in them it's ok too, you just use filtered water instead. My coconuts never have enough milk in them so I have to use filtered water in addition to the coconut water.
Remove the coconut meat, there's no need to remove the brown "skin", it'll make no difference to the milk. Rinse them in water to get them clean. Break into smaller pieces and put in a blender.
Add the coconut water you drained out before - pour it through a sieve to get rid of any coconut bits & hair. If you need to add some more water, add filtered water. Start with about 1 cup of liquid in total and add more if you see you would like a more diluted milk. I usually add enough liquid so that it almost covers the coconut in the blender. Blend until you have desiccated coconut, it only takes a couple of minutes.
Pour the milk into a glass bottle and refrigerate. It keeps for about 3 days in the fridge.
See how to make your own desiccated coconut here (coming soon).