I have just fitted a door frame and hung the door to the wall under the stairs in my house. As it was being used as storage, it started to look a bit messy. For some reason, the wall is way out, which is brick by the looks of it. so if I were to plumb the casing up and fix it true then I wouldn't be able to fix the architrave and it would just look messy (The wall is to bad to even think about scribing the architrave) Anyway, i've just fitted it to go with the wall and hung the door. It doesn't really look that bad to anyone else (the missus is happy with it) and you maybe wouldn't know unless you saw the door close on its own lol. I was just wondering what you would do if this was a customers house and you had to do the job. Obviously, you should make sure you fix everything plumb, but what takes priority. I usually work on shop/pub ref-fits, where most walls are studded and plumb anyway.