Learning spoken Chinese

A thought just occurred to me. When I was on mainland China some years ago it was common to call everyone who’s name you didn’t know ‘mei nu’ or ‘shuai ge’ (regardless of their attractiveness). I thought this was both a nice thing to do and incredibly convenient. I don’t otherwise know how to say ‘hey, you!’ in Mandarin.

Can I do this in Taiwan, or should I say something else?