I always interpreted 何 as "what" and "どう" as more of a "How or How about?" and thus was under the impression that if one wanted to ask "What will you do?" or "What did you do?" you would say 何をしますか ...
I've come across several instances in manga where the simple question of "で?" is used. What could it mean? I'm guessing it means something like "Is that so?," but I'm not sure.
I've read on Stack Exchange that どうやって can be used to mean "what did you do in order to x" どうやってお医者になったか? — What did you do in order to become a doctor? This definition makes a lot of sense to ...