In most English-speaking contexts, you would not use any specific term of address. To call 'Waiter!' or 'Waitress!' for example, would sound very rude and condescending. Most serving staff would make a point of serving you as slowly and ungraciously as possible if you tried to attract their attention in this way. If I were working in restaurant and a fellow native speaker called me 'Waitress' I'd seriously consider spitting in their food. If it were a non-native, I'd make an allowance, but it would still not make me feel kindly disposed towards them.

Jmat and Aegis both suggested 'Excuse me'.  I'll add my support from a third continent and say that in the UK, as in Australia and the US, a simple and polite 'Excuse me' is the best way to get prompt and friendly service.

I'd just say "Excuse me please!" as they walked by, then procede to ask or tell them what I wanted to.

"이모" Korean call waitress '이모'. It means 'aunt'

HI, I am not sure if I understood the question, anyway I am going to answer in two ways:

We usually call the waiter\waitress:  Mesera (spanish)

But if wen want to call a waiter\ waitress  for a service like order food or help for something,  we just rise our hand until the person see us.

Good night for everyone.

@Hunter - We're no really big on titles here. Like Jmat, I normally just say "excuse me".

Related topic - I think it's really funny how Chinese always tell their servers to "hurry up". Here, that would be rude. If you want fast service because your time is limited or something, here you really should explain that to the receptionist when you walk in, and confirm that you'll be served quickly enough. Of course it's ok to complain if the service is unusually slow.