Well, revisions are when you want to fill in the gaps that make the story jump forward faster than it should. You're going to have to find all of them, including the ones that you didn't leave on purpose.
You know that fast read I mentioned for Flow? Well, this is also sort of a flow issue too. Missing scenes interrupt the flow, so they're actually easier to feel than the other flow problems. So when you're doing a fast read, make note of the missing scenes as you go.
But do NOT stop reading to insert the scenes, because you'll just be interrupting yourself.
Look Out for These:
1) Scenes you left open for some reason, meaning to get back to it later.
2) Areas in the story where it feels as if part of the story is missing.
3) Moments that are summarized in a scene, but that feel as if they should be expanded to do justice to the story.
How do you spot the gaps in your story?