When I finish my drink, I've often heard waitresses ask me: "Вы повторите это?" or something like that (maybe I heard wrong). The problem is I don't know how to ask for another drink. Do I say "Я повторяю это" or "Повторите это пожалуйста"?
"Я повторяю это" means "I repeat saying this"
"Повторите это пожалуйста" means "Please repeat what you just said"
"Вы повторите это?" means "Will you repeat what you just said?"
If the waiter hears the first one, he/she will think that you are getting angry about that they do not understand or hear you. If you say the next two, the waiter will repeat what they said before that.
If you want another portion of drink or food, you can say "Дайте ещё такое же"