Protein shakes...smoothie consitancy?

Ok I doing the protein shakes and I am not sure how to make it like the consitancy like they have it at the smoothie shop where they are icy and not milky or thick.  Any suggestions? 

Lots of ice, high speed on the blender, and blend for a minute to minute and a half.

I'm not huge into shakes, but they must be "just right" for me to drink.... I have a high powered blender (gave away my crappy "magic bullet"), fill loosely to the 2 cup line with ice, add liquid to the 2 cup line & 2 scoops of powder.  Blend until there are no ice chunks.  Might have to scrape the sides a couple times if it is too thick.

I always freeze the milk I use to make the shake.  Ice seems to water down the flavor. 

 Since my surgery the icyer the better.  Temps really seem to bother me for some reason not sure why.  I really thin the liquid out by adding extra water, My shakes usually end up being between 20-30oz each.  

I have receiently found a premixed shake that I love love love its gnc total lean 25 tastes great and takes all of the guess work out of having shakes.