Some problems with fan productions are easily identified and can be easily improved upon (sound, for just one example). But editing is in my mind the toughest issue to deal with. Good editing requires a high degree of technical skill and it also requires a great feel for a film's pacing and structure. Even if there are no glaring errors such as jump cuts there are subtle mistakes that can distract a viewer even if they're not sure what the problem is.
Editing is an art, it's true. I touched on this in my review of "The Night the Stars Fell From the Sky" (link)
, where I felt the editing actually hurt the film.
A slim volume I highly recommend to beginning filmmakers is Oscar-winning editor Walter Murch's In The Blink Of An Eye: A Perspective On Film Editing (link to Amazon page for the book)
, which isn;t a book about the technical act of editing but rather about the art of editing, and approaches to it. As the title suggests, one of his observations is that oftentimes you can tell when to cut because the actors blink before and after a thought. If you watch people in conversation you'll notice that when they're passionate talking they will hardly blink at all, but the moment they complete the thought, blink.
Just for reference, here are excerpts from notes on various Exeter edits I sent to Scott Cummins:
3:40 Around [dialog] there’s too much cutting. I know none of the takes are ideal, but there are just too many jarring angle changes for no apparent reason. I realize that this is because the footage is not ideal, but the edits really draw attention to themselves. As they say in the record biz, if you notice the edit, then it’s not working.
at 08:17 You need to cut off the first 15 frames of this shot of Garrovick and then it will be fine.
at 08:23 You need to cut away from Cutty a few frames earlier because I register his eyes moving the follow Garrovick, who doesn't really move much until the next shot
at 08:31 The cut goes to Garrovick when he's half in the frame. Is there any way to roll-edit this cut to avoid that?
09:44 I'd trim the head of the corridor shot a hair because we only barely see the one crewman as he exits, so we either need to see more of him or none.