Re-watching Star Wars Episode IV, what I'm struck by most is how some of the most endearing characteristics of the characters are things that were not, or seem not to have been deliberately decided. The words "over-produced" often apply to movies where decisions that could or should be left to the actors, or in other ways done naturally, are instead done according to some formula or theory as to what would look best.
For example, when Han mumbles to himself in the cell block before blasting the comm console, you almost feel that you are catching him saying something. This is in sharp contrast to most modern movies and television, where every line by every character in a scene is equally easy to understand, almost no matter the circumstances--it is unnaturally easy to hear and understand the actors given the circumstances. This isn't some egregious problem with modern production, but it does clearly suggest that producers are very much "second-generation"; they saw idiosyncrasies and inconsistencies as a failure of first-generation movies and sought to eliminate them.
Compare again Luke in the hallway shortly after, saying something that is almost never said in film or television: "What's that? I didn't copy." Asking people to repeat themselves is normal even in relatively quiet situations; it is perfectly understandable that in a firefight it would be almost impossible to hear over the noise. But modern movies eliminate the inefficiency that is this sort of verbal repetition, real or implied. The result is a cleaner, better-produced, second-generation movie--one that lacks a very understandable conceit that just happens to be ridiculously common in real life.
There are other things. Things unsaid, things essentially pointless from the perspective of script but meaningful in context. When Luke sits dejectedly at the holotable after their escape from the Death Star, Leia drapes something like a small towel or blanket over his shoulders as a comforting gesture. Within two minutes, he sets it aside to deal with the incoming fighters, and it never reappears. It is not added to the movie to say anything, it is not added to his character--it happens because it is natural.
I like that about the movie. I wish that there was more natural action in modern movies. I worry that people involved in filmmaking are too worried about proving that they're worth their paycheck, given the large industry that has grown up around it.