Might want to try looking at the model in a mirror... This changes your viewpoint of the model and allows you to spot things you never noticed before... Your eyes develop a "memory" causing you to gloss over some things, and the mirror image will help eliminate that tendency...
It also helps to know when to say "when"... This is a valuable ability that all experienced modelers have developed over the years... I've been building since the 60's and hope one of y'all will lemme know when you find it...