I'd like it if they only appeared in a two parter or something, with the first part being one of those episodes centralised on a one-off character nothing to do with the Doctor, like the ones with the weeping angels. So you see the view of the Daleks from humans who have no chance of stopping them, as they just obliterate everything and anyone that they come across. I think that could re-establish a bit of fear about them, and would lead the second episode of the Doctor v Daleks actually having some tension.