Re: crown moulding
It will become self evident when you start trying to cut your crown why it is put in the saw in a certain manner. Orientation in the saw will depend on whether you're cutting an inside or outside corner.
What I recommend you do is forget about right side up, upside down, backwards, and every other direction and start by cutting yourself some template blocks for an inside and an outside corner. The template blocks will remove ALL of the guess work out of the equation, making it impossible for you to make a wrong cut. Once the templates are cut, mark them as to being an inside left, inside right, outside left, or an outside right.
And because the written word is harder to understand than pictures and videos, I would recommend you look at YouTube for some vids on the subject for clarification.
Also, you may want to consider coping your inside corners because they have less of a tendency to open up with expansion/contraction.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!