Of course, there's no guarantee that you, fortunate soul, will envision the exact thing you need as you happen to come to that place in the manuscript, or even that you can jump to that point and slither it. You might not even know what, exactly, is the point at which you could slot in some absolutely vital foreshadowing.
So what I do is write down a note when I have the perfect gem-like idea of something to do.
And double-check the list to remind myself of things to do in as I revise.
And then, when I have done something I thought of doing, I cross it off the list.
This last technique does not work perfectly, but it's better than nothing. Otherwise I look at the note and think "I have to fit in a clue that John has a grudge against Jack because of Jack's mother" three or four different times and slip it in every one. This doesn't work as well as the "write fat revise lean" principle; usually, it only needs to go in one place, and by this point, I can work out the best place for it.
Rereading the novel at a canter, to get all of what you really wrote in mind at once, is one way to filter them out, but getting rid of the note reminding you to do is even more effective.