A tip, not a trick, is to read the build manual and study the plans. Know and understand ahead of time exactly what the instructions are asking you to do. If you don't fully understand what the next step is and why, ask somebody before you make a terrible mistake. I assume Tower trainers' manuals and plans are written and printed by the same folks who do the Great Planes stuff. They are fairly straight forward and easy to understand. Know exactly what you are doing before you pick up the glue.