When I bought my apartment the lovely old double doors that divide the living area from the bedroom had reproduction stained glass panels. If you're unfamiliar with this sort of glass, it's basically glass with a design printed on the back - made to look like stained glass, but actually fooling no one.
I looked into replacing it with a translucent glass with a simple beveled edge, but it was ridiculously expensive. So instead I had more budget friendly glass installed (less than half the price) and covered it with Emma Jeffs' beautiful Otto window film. And I think that the result looks so much better than the plain/expensive glass would have. The white walls and doors also make a big difference - previously the walls were pale blue and the doors were cream.