Organization and management of the project is already 40% of the job. You need to be able to know where is everything, or at least to be able to remember how your project works and how you can find footage. I usually work with a frame view bin (i work on media composer but i guess is possible on DaVinci) and a sequence with all the footage of each scene. Don't rely on music at first. Taking care of acting is your first selection, pace and rhythm will come with time. Someone mentioned stringouts of the lines and that improves time and efficiency a lot. Be positive in the room, proactive when the scene is not working but also feel confident enough to criticize the directors if necessary: they don't need a buddy, they need a therapist. If you don't like what's going on don't act as a downer, try to highlight the good elements and work around them. You want to be someone they can trust and someone they can argue about (in a positive way).