I am frameing a gas fireplace im a masterbedroom which will have a
flatscreen over it with a small mantle. I am going to use cultured stone to
finish the face of the wall. the wall is about 6 feet wide and is 8' tall.

How do I go about figuring what would look good in proportions? ie how do I
determine the height of the fireplace and placing of mantle and tv to look
good? Are there any standard guidelines that builders use?

TIA