I've already spoken about gaps between scenes. I've already spoken about flow. What could there possibly be left to talk about?
Well... I'm talking about positioning and location, or other physical aspects.
Of all the things that really get me out of the story as a reader, Positioning errors probably go into my top twenty list of pet peeves.
I HATE when a character is sitting in one place, only to be revealed on the other side of the room two lines later. Or when a character is grievously injured, but with the injury never referred to again.
The reason why positioning and location is so important to me: the way I read. I can't tell how other people experience reading, but to me, reading is almost visual first. In other words, I must be able to see what's happening in my mind's eye.
So the moment a character isn't where he/she was a second ago. Or doing something that shouldn't be possible because of what happened seconds ago... Yeah. It stands out.
Luckily this is pretty much a seek and destroy sort of issue, so once you find something wrong with your character's positioning, location or something like that, the solution can be as easy as deleting a contradiction. If the contradiction is about a lack of something, the solution is a bit more complicated, since not only do you have to write it in, you might have to work it through your whole story.
Look Out for These:
1) Characters suddenly being somewhere far from where they were moments ago.
2) Characters doing something that's impossible given recent events.
3) A lack of continuity between one action and the next.
What was the biggest mistake you made about positioning/location?