I add in along with water about 6-7 ice cubes and leave it to mix for about 50secs, it comes out a nice texture, tasty, and d-e-l-i-c-i-o-u-s....and it´s a great start to your water intake for the day!! 1 Ltre and 1/2.
I do about 400 ml's as I find a pint too weak, but at the start I found 400mls too weak, so maybe it's just a case of slowly adding more until your tastes change
I agree with Dancings suggestion though of having a hot shake (Vanilla/Choc or Toffee and Walnut) with a spoon of coffee.
I can usually make 2 large mugs of drink from one shake then, which really fills me up
I use a pint of water to either a half or whole pack. Using half a pack is fine now but I tried it when I started and it was awful - you have to get used to it. I use a half pack at breakfast time so I can have supper too, lol.