I'm trying to recreate a Starbucks caramel coffee frappuccino, but it's coming out awfully watery. I've watched them make it and here is what they do, as far as I can tell:   half fill the blender container with ice pour milk on up to half the level of the ice add some (hard to see how much exactly) coffee from a tank labelled "frap", which I assume is just regular cooled coffee add some squirts of caramel syrup blend.   Yum, delicious. But when I do this, I get a very watery result which is not thick and creamy like theirs. How can I improve it? 
Aside from ingredients, you should also consider the blender. I don't know what brand of blenders Starbucks uses, but they're clearly something that's a) heavy duty and b) high speed. Blending the drink at very high speed may result in much smaller bits of ice and a drink that seems smoother than what you can produce with a consumer blender. 