For some time I have been trying to figure out how to create the two doors shown in the movie FOTR. One is just to the left of the set and is surrounded by a wooden door frame. The other is located in the center area of the set below the Narsil statue and is observed during the council scene when Merry and Pippin are spying on the council and spring out to demand to accompany Frodo on the Fellowship trek. It is surrounded by a stone framework.
My final approach was to layer a cut out frame over an inner inscribed sheet. This is my final effort.