I do not put anything in my mouth called "tall". Walking up to a stranger and grunting "tall, black" is only a smart thing to do in comparison to the alternatives - statements like "tall, with cream".
You might think "tall, with milk" would be acceptable to a guy like me. I suppose hypothetically it would be. But the woman behind the counter usually weighs more than I do and has a face that reminds me of my cute little pug back home, so until she's as tall as I am with some nice cleavage, I think I'll forgo the whole milk and go straight for the Columbian bean juice.
I will ask for a "grande" when I'm in Mexico. I will not go to Mexico until I speak Spanish. Unfortunately, my Spanish doesn't go much beyond "yo quiero Taco Bell." Therefore, I will not order a "grande" any time soon.
I order things by the sizes on a diner's menu: small, medium, and large. If there's only two, I skip "medium". If there's more than three, I add "baby" or "extra large" as it seems appropriate. I will often use "super size" instead of "extra large". It's alliterative, and McDo's is even more universal than the English language so there's rarely any confusion.
This is not a complicated system, people.