Though I'm going through the film frame at a time, my process for determining what needs adjusting is simple: I watch Star Wars, in real-time, on a regular consumer television (albeit calibrated). As soon as I see something that clearly looks wrong, I open up the film and figure out why. Based on what needs fixing, I either correct it, or leave it alone. I notice that watching Star Wars on that same consumer television set to the factory default settings reveals a ton more errors as well, because of the excessive contrast and gross over-brightness of the default settings. So to be safe, I fix those too. I stop the very instant that the drama plays out smoothly again.
A typical example is something I "corrected" yesterday, in the fight between the Falcon and the TIE fighters. Just before the TIE's fully attack, the Falcon gets jolted by some nearby laser blasts. Because the shots of Han and Luke in their gunner seats wasn't filmed with camera shake, they attempted to add some by rocking the frame back and forth in the gate a bit. It's an extremely cheap, 2D looking gag, that looks really silly. There's no way you can miss it, and at that moment, you're not thinking about the impending attack of the bad guys, you're thinking, "what is THAT? That looked stupid..."
Today, we have tools that let you add motion blur in post by analyzing the motion of individual pixels over a sequence of frames. So I added post blur consistent with the look of the intended action in the frame. It's not a perfect fix, because there's no parallax shift between the foreground and the background elements, but the fix, while subtle, makes all the difference. You don't go, "hey, there's some blur!" You just see the guys shaking with the laser blasts, and you're waiting for the TIEs to come. The effect may not be perfect, but it's enough to let you stay in the drama, and stay in the moment. And THAT is the goal.
_Mike