One former Starbucks employee revealed in an interview with New York Magazine that, unless you know how to make the drink or know exactly what's in it, it's best to avoid the secret menu. Baristas at Starbucks can make numerous different drinks, but it's best to give them the ingredients rather than the name. They might not know what a drink is based purely on the name given to it on a secret menu. Per Quartz, there are over 170,000 different possible combinations that can be made, so it pays to be specific. 

Take, for example, the Blackberry Cobbler Frappuccino. Outlined by Glamour as one of the best secret menu drinks, it involves starting off with a Vanilla Bean Crème Frappuccino, with white mocha syrup added — the amount depending on the size of the cup — and blackberries too. Rather than just asking for a Blackberry Cobbler Frappuccino, it's best to explain what's in it, and how it's made.  

If it's busy, and the staff seemed rushed off their feet, it's probably best that you don't order something ridiculously complicated. One employee told Thrillist that they might "resent you slightly" if you do so, but that when it's a little quieter, they're usually happy to make something a little different.