I'm going to put crown moulding in the bathroom I'm remodeling. While
I was sanding the moulding I realized I didn't know which way was up.
I've been told that for years but never believed it.

With some styles such as dental moulding it is somewhat clear which
way it should be oriented but with other styles I haven't got a clue.
Is there a rule of thumb to tell which side should be up or is it
primarily what the individual prefers?

Thanks,
R.C.