The point is that this common sense really differs between countries. Consider levels of politeness and indirection in Russia and America, for example.
Unfortunately we have lost the addressing here in Russia during the stormy revolutionary years (it was rather “сударыня” и т.п.).
The most universal and safe way - in my opinion - is to use indirect phrases like “Простите пожалуйста, не могли бы вы мне подсказать…” and so on. At leas it is what I hear here.
“Молодой человек” and “девушка” for me is strongly associated with either a) elderly people where it is perfect, or b) with - excuse me - not well educated and somewhat provincial people. Like in “молодой человек, подвиньтесь!” or “девушка, вы на следующей вылазите?”.