Standing in front of a board you have never read before is its own small stress, especially with somebody waiting. So here is the short version, by situation rather than by ingredient.
You have just woken up and you are not really awake. Most people go for something sharp and cold. Citrus, ginger, something with an edge to it. It is less about what it does and more that a mouthful of something cold and sour is very hard to sleep through.
You are actually hungry and lunch is a while away. Take a smoothie. It is thick enough to be a small meal, and it lasts longer than a juice does.
You have just trained. This is what the protein shakes are for. Nothing complicated: something to drink straight after, while you are still working out where you left your keys.
You are on the way somewhere and not stopping. Take a bottle. That is the whole point of them.
None of these are rules. People order smoothies at seven in the morning and cold green juice after the gym and both of those are completely fine.
And if none of it helps, there is a three question thing on this site that will pick for you, or you can do what most people do in the end, which is ask whoever is behind the counter what they would have.
That is the thinking. Here is the part you can actually order.
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