Lisa
When I make the shakes up I put a few ice cubes in a jug, add the water, then pour the powder on top, whizz it with the hand blender until all the crunching noise of the ice stops, pour into a glass (or two) and enjoy!
I think it tastes so much better than just mixing it up without ice. It seems to make it thicker and it's like a really nice smooth cold thick shake. Have you tried it this way? If not it might be worth a try.
I hated the shakes when I made them up with just water and the powder. I can't believe the difference when I make them up this way they are gorgeous!
Hope that helps a bit
Mocha
PS: I do this with soups too, not the ice obviously, but I put just boiled water in first, add powder, whizz with blender till smooth.