I've just written a synopsis of the book, which always helps to get it clearer in my mind and enables me to identify any faults in the plotting. My usual move at this point would be to carry on reading it through, back and forth, editing, until sick of it, then put it to one side and get on with something else. I would then print it out a month or two later and cast a fresher eye over it. Also, reading from a typescript rather than a screen also enables me to pick up on any problems. However, this is due to be published in August, so I need to send it to Macmillan soon. The fresh eye re-read will have to wait until after scary pencil time.