The first thing to do is to read/understand the requirements for the show/fair you are entering. Of course, all workmanship needs to be to the highest degree possible. Some quilters will do multiple blocks, even multiple quilts before submitting one. This is a pretty good breakdown:
https://quintessentialquilting.com/b...judging-part-2
Originality is big. A kit has to be done beyond perfect. A well known pattern should reflect the maker, and not the designer of the pattern. Not to say you can't win with either of the two.
At least in my area of the country, applique is always a viewer's choice winner. Of course, workmanship needs to be high, but just a simple vine and flowers type border around a pieced sampler always gets more votes than a purely pieced project.
A number of years ago, I got called in as a last minute replacement for a county fair when one of the judges was in a car accident. I was known to the other judge and from outside the county/primary guild of that area and available with limited notice so was called... We had a very clear package of judge instructions. Our winner was not the people's winner and not exactly to my taste/color preferences -- but it was just truly exquisite. I've also had the opportunity to compile quilt guild show votes.