Have you done a search of the other threads asking this question?
http://www.quiltingboard.com/search....archid=8454190
http://www.quiltingboard.com/search....archid=8454221
I attended a lecture on what judges look for given by an NQA certified judge. Bottom line is this: The primary thing to remember is that they are not judging HOW something is done, but how EFFECTIVELY it is done. A simpler technique done brilliantly will win over a more complex technique done just passably, all else being equal.
She also said that when it comes to Best of Show, it boils down to comparing two qualities among the class winners: degree of difficulty and complexity of design. The more decisions a quilter has to make in the creation of a quilt, the more chances that something will be “off”. Making the right decision each time counts for a lot!