I've done a lot of screenplay work, but never any stage play, so I'm wanting to explore that area. In general, when describing a setting, is it better to describe what the imagined scene is, or how the stage should be set up? For instance, would you say: "Gios: A quaint Italian restaurant on the Upper West Side. It's a quiet joint for the locals, where the regulars get seating upstairs." or: "An empty table for two, with checkered table cloth, stands at stage left. Upstage, a tall platform represents the second floor. Several more tables here." I haven't been able to find any sort of consistency here.
Perhaps @mammamaia will correct me on this, but I've been told to use the latter, with possibly a tiny bit of the former mixed in. E.g. "A quaint Italian restaurant. An empty table for two, with checkered tablecloth, stands at stage left. Upstage, a tall platform represents the second floor. Several more tables here." You should never write description as if it's fiction, like your "It's a quiet joint for the locals, where the regulars get seating upstairs." That's not necessary to know, so it doesn't need to be added. Although, I have to ask, if it's a quiet place, would the stage need quite so many tables set up? If you're having trouble, look at some stage plays in more depth; notice what's being described, and what props are being mentioned for the particular scene.
My experience has been the same as @Thomas Kitchen's - whatever is said about the setting is in the form of stage setup. There are also sometimes specific instructions that the curtain be open as the audience enters the theater (Herman Wouk's The Caine Mutiny Court Martial) or action that occurs just as the curtain opens (Moises Kaufman's 33 Variations). However, I, too, will defer to the wisdom of @mammamaia on this for current works.
you both get an A+, kids! rumwriter... yes, the stage directions are written for the director and technicians [propmaster/LD/wardrobe/etc]... and should be clear and concise... feel free to email me if you need any further help in writing your play... love and hugs, maia maia3maia@hotmail.com