That said, I have Scissors, Ruler (only to use to draw straight lines with ULTRA fine sharpie ) NOT TO FOLD!!, Exo-knife to cut half way through the paper- super easy fold then and very clean looking,
If I read that right, it sounds like you are using your x-acto to pre-cut your folds, so that they are easier. That's a good idea with plastic, but not paper. Paper would make me nervous. Why not use a pen to trace the line? That's what a lot of people do here; I myself did it for some of the finer detail pieces on my build.
You do the same thing your doing now, (trace the fold line with the pen, pressing down on it enough to leave an indentation, thus making the folding easier and neater) but you don't use the knife so you don't have to worry about piercing the paper.
Just my thoughts; looks good otherwise.