Derek first and formost is the quality of the build. Unless you are at the Bill Geary level of model building forget opening anything. I have judged many shows over the years it is the "quality" of the build in the areas of
Fit (no sprues or parting lines), Finish (glass smooth paint, no glue marks, no trash in the paint) that makes a quality contest model.
Build a box stock (exactly as the kit instructions tell you) and learn the fit & finish before tackling more complcated build procedures.
Here is one of my recent models: