in my native Russian we frequently use the combination of the two marks "?!" for emphasis. For example, if I wanted to show in writing that somebody's question sounded very emotional, I would punctuate it like this: "What?!"
I came across this blog post (in Russian). It says that this kind of punctuation (?!) is only typical for Cyrillic languages as well as Latvian (claiming that in Latvian the order of the marks is irrelevant, e.g. it's possible to write "What!?"). I realized I've never really paid attention to it. So my question is, what is the tradition in your native language? Would you put both marks? Or just one?